Building my own solar power system
medium.com
medium.com
We’re running 6 inverters on our primary system in a three phase configuration, 35kw of panels and 160kwh of lithium iron batteries. About to add an additional 20kw of panels and a test bank of LiTo cells.
Our panels are a distributed set of rooftop mounted panels on various buildings, which also serves to shade the rooftops reducing cooling loads.
We still have to run a generator to supplement charging on dark overcast days, but it’s typically about 100 hours a year. Hooping to get that running on biomass eventually.
It’s strange to me that people in rural areas pay for electricity. It makes no economic sense, at least here in the Caribbean.
This comment was very confusing until I read the second sentence. Electricity prices in the Caribbean are very high, and I can only imagine that rural areas are even worse.
Where I’m at in the United States a typical electric rate is around $0.10/kWh. Paying that nominal amount and avoiding the need to service additional equipment and deal with backup generators is an easy decision.
https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...
They proposed to update it to .15 so they could trim trees around the lines a little better, but it got denied by the co-op members as unnecessary.
Pge felt the same way and it did t turn out so well for them. I hope your coop is never found to be at fault for the next record breaking fire…
At least where I was.
Separately for "clean power", Off peak is 0.13 and peak is 0.17
So that's a combined 0.57 and 0.65
We bought ours in '10 to offset high AC use in the summer - we were paying $1000-1500 a month for 2-4 months in the summer. The first few years, our "year-end" balance was < $1K (we just paid minimum payments the rest of the year), so I figure we easily saved $2-3K/year in those early years, and after the incentives in those days, we paid ~$14K, so maybe 7 years to pay it off. Our year-end balance was more like $3K the last time, and I think we're still producing 80-90% the same power, but PGE keeps changing the plans around. At this point, I'm interested in upgrading our cells from 300W to 450W, but I'd only do that with a battery system that also stores energy so that we could go more or less entirely off-grid. But probably need a new roof first..
My California rates are .50/63 off/on peak
"Jealous" is not the term I'd use...
(The price of electricity is already pre-approved to increase 5% a year, so actually my savings will be more every year than the year before)
Solar can be worth it even when power is cheap.
Not so fast. Zero emissions, yeah. But they have damaged the habitat for some bird species.
> avoiding the need to service additional equipment and deal with backup generators is an easy decision.
We've got a house in a very small town (pop. 100) and there are solar panels on a ton of the houses there. I've asked a few people about it and it's 100% for grid redundancy. Sure, they save a bit of money on their power bill, but they're basically using the panels and batteries as an alternative to a backup generator. Winters are quite cold here and having enough power to run the natural-gas-fired furnace and a few light bulbs is a huge win when the power inevitably goes out. Lots of people have small generators kicking around too (like the Honda EU2200 that RV folks love) but the solar install has seriously cut down on the need for those.
I always assume when people on here are talking their 'rates', that they are usually NOT factoring in the delivery fee unless stated.
But maybe some places are just really THAT cheap.
I'm not fond of high electric rates, but in addition to generation those rates amortize and distribute the cost of storm recovery. A home or business with grid-tied solar pays interconnect fees for the option to get paid back a little for excess generation, and the option to decide to switch back to 100% grid power if a storm damages the on-site panels.
Not exactly when it is a farm out there away from a town.
My experience is from a different era (90s) and a different kind of farm, but I spent a bunch of summers in one, which had power outages whenever the monsoons picked up.
The trouble was that there was a single line feeding the farm from about 6km away, so if that went down a single farmowner complained - the rate payers who were in a denser urban area always got priority, because there were 600+ people who shared a transformer.
The generator ran a lot when winds knocked power out, but the generator only ran when there was a big power need like running the well pumps or one of the winnowing mills. Even the winnower had pedals, because work doesn't stop.
Every bathroom had a light with a 30 minute battery in it, which came on when the power went out - I guess if they had LEDs those same batteries would be 6 hour lights.
They would have killed for solar + storage, because shipping fuel in for the generator was one of those annoying things you had to keep doing over and over again.
The urban rate payers also subsidize the rural ones, so it makes sense that they'd be front of the line.
I don’t worry about outages much in my current home because the main line to ~1000 houses goes right past me, and I’m fed straight from it. If I’m out, it’s a very high priority line. Worst ever was about two days. It helps that our worst storms are usually in spring, so weather is mild.
I think I am much less remote than the poster, and I can easily lose power for a week or more after a winter storm. Considering that they already have generators on site that can manage the full load, they probably have much better up time than the utility electricity provider.
We can run on generator to charge the batteries for about 2 weeks on the fuel we keep. Other than that, we rebuild what isn’t broken and later buy more panels. Most of our mounts should be good to about 150mph, but trees also fly so?
Good news is we can buy panels here about $120 for a 500 watt panel.
Also we have some geographic protection from the full brunt of a storm , as we are in a mountainous eddy zone that typically sees about 30 percent of the coastal and mountaintop wind speed when a cyclone passes nearby as they frequently do.
I don't have the skill to do it myself, but I'd love to see an analysis of whether it would make more sense at this point to do solar/wind + batteries and backup generators for at least the smallest and most remote communities.
https://www.dcceew.gov.au/energy/programs/regional-remote-co...
and moved to the pilot phase:
https://arena.gov.au/funding/rmp/
A review of some of the feasability studies carried out in phase one:
https://www.sciencedirect.com/science/article/pii/S221462962...
Ahh, the accounting style of hobby projects. I’m very familiar with this because I do it, too.
Nothing ever feels expensive if you just never add it all up and value your time at $0 because it’s fun.
We do buy carefully, and all the engineering is done by me. We have employees on the farm so much of the labor of installing underground cable etc was “free” (lol).
Still, we are miles ahead of our costs if we were hooked up to the grid (which also would have cost us an additional $20k just for poles to get close, and we still would have had to bury the cables on campus along with the water and data, if we didn’t want ugly poles all over, so that part is a wash)
I spend about 4 hours a week on utilities based projects, mostly engineering monitoring and control systems so that I spend less time working on the utilities. (So, futzing around with electronics because I have an excuse to) it feels like meaningful work that I care about, so that’s nice.
I've looked at it from a bunch of different angles and keep coming to the conclusion that for rural and suburban areas with the space for panels, off-grid solar is the future.
I don't know if you were being ironic or not but... that's an absolute truth. Our free time doesn't have a fixed rate. It doesn't have a rate at all. What you do during free time can be basically seen as either:
* a chore you don't like to do
* something you like to do.
Any task can swing between those states depending on your mood. If installing your own solar plant or self-host your server rack (as OP is doing) is something you enjoy doing, then yes, it costs exactly $0 in labor.
Also to be clear - good on you for building out rural off grid electrical. Its a fun project and satisfying no doubt (outaide of costa)
I’ve spoken to people from Rural Georgia (which is about an hour from Atlanta depending on the direction you’re driving) in Microcenter that are usually there to wire up their farm or factory with sufficient network capacity to keep production rolling. They have mentioned that they have had to do their own trenching for last mile for various services. Sometimes that means they literally drive down to Herc rentals, pick up a trenching machine, and do it themselves since the wait for someone else to do it is months away and that’s a long time if your business needs internet, water, power, etc.
Is there any documentation of your solar microgrid systems for learning purposes? Or better can anyone visit your farm for learning the microgrid systems?
I just found these article back in 2017 and 2022 on microgrid installation in the Caribbean and they looks like promising off-grid solutions for tropical islands [1],[2].
[1] Why Solar Microgrids May Fall Short in Replacing the Caribbean’s Devastated Power Systems (2017):
https://spectrum.ieee.org/should-a-devastated-caribbean-leap...
[2] As rich nations haggle over climate solutions, storm-ravaged Caribbean is taking matters into its own hands (2022):
https://edition.cnn.com/2022/11/15/world/caribbean-solar-pow...
When I took a vacation to Aruba, I was very disappointed to see very limited solar and EV adoption. Public transportation (buses) were running on gas, as were most personal vehicles.
It was nuts to me considering there was only 1 overcast day out of the 7 I was there, and you definitely don't need any energy for heating, ever.
It’s a ratchet:
Need more power: Buy more panels, they are cheap! Need more power: Buy more panels, they are cheap! Need more power: Buy more panels, they are cheap! Need more power: Can’t buy more panels, need more batteries to stabilize the system. Thankfully , batteries are getting better and cheaper! Lots of power, so much we need to find new ways to benefit from it! Need more power: Buy more panels, they are cheap! ……
The economics of panels are basically 20 percent APR here over 20 years. Over 40 years it drops to around 10 percent for out of service life panels.
We have a fair bit of vertical scale in the terrain here. We extract our water from a shallow well in a natural crevasse between ridges. It is made of concrete blocks stacked in a circle, filled with gravel and pinned with heavy rebar. The above ground part is finished in a regular fashion, with the blocks filled with concrete and a concrete cap. The well is built of a circle of 12 blocks, and is about 16 feet deep- where we encountered hard bedrock. An underground stream flows over this bedrock, which we extract from.
This raw water is pumped to a 300 gallon manifold tank about 160 feet above the extraction point using a 1HP centrifugal pump. From there, it flows down to the processing facility, where it is sediment and carbon filtered before flowing into either the 2600 gallon cistern, or back up the hill a bit to a 450 gallon upper campus distribution tank. Water passing through the processing facility is filtered and chlorinated, with the exception of the upper campus water, which is only filtered.
The upper campus water flows to cabins in the upper campus, and also serves as the input water for the RO system. The RO source water is pressurised by another centrifugal pump to 70psi, and is fed through a pair of 150GPD membranes after being filtered to 1 micron and passed through another carbon block. We run a 4:1 “waste” ratio to give us good life on the membranes (typically a year). The mineral rich “brine” flows into the 2600 gallon cistern and is used in the regular water.
We warehouse the drinking water in a 500-gallon tank at the processing facility.
There is a dual distribution system for water on campus. From the cistern at the processing facility RO water and regular water flows through underground tubing to a network of 5 utility huts where it is distributed to various homes and outbuildings. Each building then passes the main water through another carbon block to catch chemicals and chlorine, and drinking water gets mineralization and carbon again at the point of use.
The underground distribution network also carries 3 phase power, HVDC for solar, separate fiber optic networks for security, control, intranet, and ISP, as well as cat6 cables for RS485 control subsystems. The tank levels, pump controls, power distribution and usage monitoring, emergency and automatic casualty control shutoffs, etc are all operated over rs485 and modbusTCP to a server. It’s a lot of off the shelf stuff and some custom stuff that i have built. Someday I need to do a write up on that lol.
Anyway, that’s the view from space.
Also, yeah, I know. Wordpress wasn’t a great choice even years ago when I set up the blog, but I was going to self host as a static site “soon” anyway and I needed to get started… almost good enough is the mortal enemy of adequate.
Would you mind sharing some more design details?
Questions that come to mind: What products are you using? Are you doing any AC-coupling between inverters? If not, are you just running your PV wires between buildings? Are you stepping up your AC voltages to 480v or so to cover greater distances with less loss? Thanks!
The panels are mostly centralized with each string being a home-run to the power plant but we are building out an additional 10KW on a rooftop about 200 yards away, so that will be 600VDC buried cable.
We are testing small ( panel-back attached )grid-tie inverters for supplemental power at point of use, but we will see how much we can add before it results in stability issues. It would be great to be able to put a panel or two wherever it’s handy and just tie each panel separately into the ac distribution.
Wouldn't it be more efficient to run direct DC appliances?
We have a building on our farm without power and it'd be ideal to be able to charge batteries and run lights at night
It seems to me that we would have to upsize batteries in order to make up for the loss in converting to AC
Can't say for OP, but DC appliances are just difficult to find, usually more expensive due to economies of scale and not as uniform in voltage (12/24/48V) as AC appliances. If your battery is in a shed somewhere it's also much easier to run a smaller gauge AC wire than setup distribution for your DC power.
Most large system are also 48V so you need to get it down to 12/24V which adds components anyway, at which point you might as well just have an inverter and not worry about any of that.
So yeah, you can get by without an inverter, but then you need a battery charger manager so as not to overcharge, and (depending on the battery chemistry) something to cut off the battery as it runs down. (Lead acid for example shouldn't go below 50%).
20 years or so ago I rebuilt a 60’ schooner, and even on that scale AC was by far the best choice. Just the wiring for a DC system was more expensive then double Refund inverters, and most of the appliances were actually less efficient, since they had their own inverters inside them (DC-DC converters). In all there just wasn’t any justification, and corrosion is another issue on boats, so we went all AC.
I really don't see why we're still using A/C inside our houses / apartments. I understand that the transmission loss is lower when sending A/C, so it makes sense, but then nearly every device in my house has their own AC to DC converter. Just have one AC-DC converter per building.
I'd like the future to just be USB-C sockets in my house. We have USB-C PD 3.1 which supports up to 48v, I imagine that would be good for all devices.
There are probably safety reasons why this future might be difficult.
I have a small mess of 12-ish volt computer/network equipment in the corner of my office and looked into running it all off of one $40 high-amp power supply to eliminate all the wall warts and bricks. By the time I figured out power distribution and termination, buck/boost converters for the things that aren't 12V, it all seemed like a lot of work compared to just spending a couple hours tidying up the cabling and hiding the wall warts.
You can live in the future now and install power outlets with USB-PD built right in, although a quick glance suggests they top out at 65W. Fine for phones and tablets, might not keep a gaming laptop charged while in use.
This requires higher voltage and robust connectors.
That level of DC is quite dangerous compared to AC for many reasons.
Also, unless you want to have 60lb extension cords the size of bratwurst, you need to go high voltage. High voltage DC is its own kind of devil, and is something I would not want in my household except in very isolated, self contained places.
High voltage, high current DC is on yet another level of mortal threat, able to do cool tricks like making extensions cords burn from one end to the other like cartoon dynamite fuses. Also, absolutely the best for accidental electrocution, severe burns and flash blindness, and setting otherwise fire resistant structures thoroughly aflame.
Also, some devices run directly on AC, or need more than USB can do, even with EPR. Since we already need AC for that, why add more wires when USB chargers are cheap and efficient and reliable these days?
1. Switching. If you go look at your favorite part supplier you can find a bunch of switches that are rated to switch 250 volts AC and pass 16 amps, enough for basically any standard household outlet anywhere in the world. Those same switches are only rated for 24 volts DC. Why? Because of arcing. AC voltage passes through zero twice a cycle, which means that any arc that may be formed will self-extinguish within a hundredth of a second. DC doesn't do that, so the arc potential has to be limited either by reducing the voltage or increasing the size/complexity/cost of the switch/relay/contactor itself. This also applies to any connectors that may be unplugged under power like wall outlets. If you want to do the same amount of work with DC as you do with AC you basically get the choice between doing it at lower voltage with thick expensive wires or doing it at higher voltage with expensive switches, relays, outlets, etc.
2. Motors. Synchronous AC motors are EVERYWHERE. They're simple, cheap, efficient, and as long as they're not overloaded they run at a consistent speed determined by the number of magnetic poles in the motor and the AC frequency. If you have an appliance or power tool that runs on mains power and does not offer motor speed control (or only offers two or three speed settings) it's likely one of these. Native DC motors are also cheap and simple but but have very different performance characteristics, no native mechanism for precise speed control, and flow current through the rotor which requires brushed contacts that wear out over time. "Brushless DC" motors are actually AC motors paired with a controller which is more or less a DC->AC inverter, adding cost and complexity that may not be otherwise necessary or beneficial to the application.
3. Voltage conversion. AC can use simple wound transformers to efficiently trade voltage for current or vice versa using nothing but wire and metal. You might have used or even built one in a middle-school era science class. DC voltage conversion on the other hand, the simple methods are inefficient and the efficient methods require high-frequency electronics which only became inexpensive enough to go mainstream in the last 50ish years.
None of these are insurmountable problems of course, especially these days when switch-mode power supplies, inverters, VFDs, etc. are cheaper than ever but they still make things more complicated and require going against in some cases multiple lifetimes of industry inertia to purchase equipment produced in much lower volumes which means higher costs, and especially for home applications where size and weight are not the biggest deals it can often be easier/cheaper to just run a larger solar/battery setup to counteract the efficiency losses.
In the RV and boat worlds where size and weight matter you'll find a lot more DC appliances, but those are also generally smaller capacity than a household equivalent.
Do you have a tech blog or writeup on what things you used, what parts broke down, or what kind of things needed to be fixed over time?
I recently got a second hand electric car. I bought an EV plug (total fucking ripoff. its a fucking plug with a contactor, RCD and a CAN interface. no way is that worth fucking £600)
It has some basic control to allow me to charge from excess solar. What is not easy to do is charge at night without draining the house battery. Its fine for me, because I have Home Assistant, with enough fiddling I can get all the systems to talk to each other to play ball. (to add to the complication, I'm on a variable rate tariff, so price can be negative or £1 a kwhr)
I would really love a "house power API" that would allow a "controller" to locally control the power behavior of all the things in a house. Because at the moment, a "normal" person wouldn't be able to charge their car and have house batteries and have solar, and optimise for cost.
This way the battery does not see the load and does not provide power to your EV.
That way you can still use excess solar (before you inject it into the mains) to charge your car + you do not pull power from your battery :)
I might ask to see if thats possible. I probably need more panels to cover the winter load.
https://agilebuddy.uk/historic/agile
has some historic prices. We still use gas for heating, so there isn't so much seasonality for consumption. (there is, but not in the same way).
What does affect price is wind. you can see in december there were both record high prices and record low. The more wind we have the cheap power becomes. so in winter its generally quite cheap, but then also it can flip and become very expensive, because gas imports are expensive.
Liability coverage, and UL certification (or UK/EU equivalent), for the company is. Though see perhaps:
* https://en.wikipedia.org/wiki/OpenEVSE
> I would really love a "house power API" that would allow a "controller" to locally control the power behavior of all the things in a house.
With regards to EV and the grid, see perhaps:
* https://en.wikipedia.org/wiki/ISO_15118
* Also: https://www.ampcontrol.io/post/what-are-ocpp-iec-63110-iso-1...
For an (industrial) electrical communication protocol, perhaps:
I have also heard that if you go all in it works much better. It does have the nice feature of diverting to other devices instead of the grid, and giving priority to certain devices.
Then for use with smart tariffs like IOG there's a microcontroller, cloud gateway for them to hook into for OCCP to turn on and off the charger when the grid is cheapest/greenest etc.
So £600 is about right, once you add in R&D, certification, profit margin, warranty claim % etc.
I wish it had all of that. I would actually pay for that. The Zappi from myenergi promises much but fails to deliver.
I always recommend hardwiring it though, rather than relying on Wifi through a brick wall.
Took me 1-2 month planning and then 3 month building it alone nearly each day. Sept 2023 til Xmas 2023. Got all the hardware from a PV dealer friend on his purchase price level. Even 24 panels I have put myself alone onto the roof. With two persons it was a bit better.
I've got: 420w x 71 Trina solar panels and two SolarEdge inverters. SE10K Hybrid and a SE17k. Also a 24kWh BYD LFP battery.
All prices without state funding: Offers from local installers for 56*410W Panels without battery were around 65k CHF.
I've paid now 44k CHF including every kind of cost associated with building it.
Should write a blog post about it :-)
Next project is a solar fence with 6kWp.
We’re living in a big river valley where we have fog from October until March. On some days in November the fog is so dense that the whole system does not produce any kind of energy. On the other days the produced kWh are enough to charge the battery.
We have a heat pump (extrem efficient), servers, one electric car, etc which consumes all together around 13MWh per year. The solar system produces around 27.5MWh. Most of the energy gets fed back into the grid.
We’re currently investigating to connect the neighbour houses physically to us. But that takes even more time here :-(
Just for comparisons sake, our 8.6kwP setup with a 10kwH battery cost us (after subsidies from governemnt) appr. ~€11.5k. Haven't received all the subsidies yet, so the total will be lower by about 1.5k (I think). Everything was done through installers, we didn't lift a finger (also couldn't, because when it comes to electricity I have as much experience as the dog next door).
If I had more due diligence before I would have scaled up the panels up to at least 10kwP, for future proofing probably to 12kwP. This is mostly just to make sure winter is covered better, as our production is really low as we have a 10° flat roof installation.
When I charge the car via battery then only down to ~75% for now. The remaining energy is needed by the house during winter months.
We rebuilt our house in the SF Bay Area in 2022 and went fully electric, no gas line anymore. It was really sad that I couldn't resuse any of my previous 12 kwh solar panels that were fully functioning and had another 10-15 years on them as they wouldn't match the new regulations.
I tried to get them installed on a separate area in my own backyard for off-the-grid charger just for my car, but you are not allowed to have a big off-the-grid system unconnected to PG&E. No electrician was willing to help with risk of losing license. The author was lucky that his dad could help with electrical.
Due to similar issues, I couldn't find anyone to take them for free as well. Demo dad was a truly sad day to watch these perfectly functioning solar panels being destroyed by a crane.
Used solar panels are a pretty brisk business right now. Lots of places are replacing their 10-15 year-old panels with new ones just due to the better efficiency and capacity alone. And now that we have over a decade of large-scale solar experience to draw from, we are finding that they tend to degrade a lot slower than expected and that the original 30-year lifespan was highly conservative. I'm surprised you couldn't find someone from out of state to buy them.
Wow these rates are crazy. A 10kW setup costs you maybe €10.000 all-in here in the Netherlands.
What's going on with these rates? Do they already include the ridiculous tarrifs?
A new battery setup for a 20kWh LFP battery + 10 kW inverter + installation is €7000 now.
And dropping, fast.
Assuming batteries and PV come from China, someone in California is making a lot of money or the government is straining the process with bureaucracy costing $30.000 per setup.
I have a powerwall 2 with 5kw panels, which I've had since about 2021. At the time it was the biggest, cheapest, had a grid isolation mode, and could be mounted outside. (I didn't trust tesla back then, and I sure as shit don't now. Moreover, once it catches fire, that shit aint going out anytime soon)
It still cost about £7k installed.
From about march/april to end of october, we are power sufficient (london, even with rainy days, gas hot water though.)
If I were to get a new system, 13kwhr of battery is something like £2k, plus inverter/charger.
The panels are dirt cheap, to the point where the scaffolding costs more than the panels. (and the mounts.)
A $45k quote would correspond roughly to 14k euro of materials.
New subsidies this year for batteries mean I can get a 15kwh battery installed for around 2-3k AUD
Under the subsidy rules for feed-in-tariffs at the time, that had to be done with an MCS approved installer. All work in England would require an approved "Part P" signoff anyway. However it did not require council planning approva, nor grid approval for that size of system.
In fact when I was first hired as an engineer, it was actually someone that wanted an electrician but hired EEs instead because they are cheaper and more readily available.
One of the worst is something like installing HVAC stuff. I got an EPA refrigerant license in 2 days of studying and then did my own myself. If I wanted to install it for a profit for someone else, I would have to spend 4 years working for someone else with a license first to get the contractor license! The end result is it legitimately cost like $700 to have a single capacitor replaced on an air conditioner, and in places like Florida if you do it for someone else without years of 'training' you're now a felon.
Where I live you can't but go figure you can become a licensed finish carpenter with a simple test.
One loophole I looked I might look into some day is moving to another state with the least requirements for a license, then getting it, then transferring it to another state, which is allowed at least here.
If you're able to get a 12kW rated full system, including racking, panels, and inverter for the equivalent of $1/W that's an amazing deal! I wish prices here were like that.
Had it for a year now. Generated 7.7kWh which is worth $950. Took out natural gas, power bill for the entire year (heat pump, elec hot water) was $1000.
Snowy mountain town in a tight valley in BC.
Markups due to subsidies are a part of it.
The other issue was just plain pent-up demand. Installers could charge what they wanted because there weren't enough of them to go around, even as everybody and their dog started their own installer business. Many of those businesses were poorly run and have since gone under, leaving the homeowners high and dry when the inverter craps out and they're told by every other installer that they will not work on someone else's install and also told by the inverter manufacturer that if they attempt to replace the hardware themselves it will result in their warranty being voided.
Customer is willing to pay 10k, state is willing to pay 5k. Supplier will charge 15k.
Assuming the base cost is 8k
Supplier A and Supplier B charge 15k and have 100 customers between them, making 350k each
Supplier B decides to undercut Supplier A, and charge 14k, and get all the customers, making 600k profit
Customer might be willing to pay 10k, but if there's two identical quotes, one for 10k and one for 9k they'll go for the 9k
- Greed kicks in because capitalism: prices rise again, maybe not back to pre-subsidy levels, but they rise.
- Subsidy gets axed: prices rise to above pre-subsidy levels.
(Note: I'm personally entirely pro "subsidize things you want more of". But that requires a stable, trustworthy government that plans on longer timescales.)
the Netherlands had a net-metering subsidiy + good competition + frictionless install and as a result we have 3,5 solar panels per person installed.
- Demand drops due to increased price to buyers.
- Prices drop so manufacturers can remain profitable.
There were no greedy people before capitalism. Of that we can be sure.
In France, the state pays max(rate * rent, cap) for apartments for students, unemployed and poor workers. Usually people don't qualify for ratio of the rent, because it's way over the cap for the subsidy. To keep up with inflation, the state re-evaluate the cap of the subsidy almost every year.
A french economist showed that there was a correlation between the cap of the rent subsidy and the rental market prices for small apartments. Of course, correlation is not causation, it could just be that the rental market follows the inflation as much as the cap. But this correlation doesn't happen for bigger and more luxurious appartments. Her explanation is that your poor household is only ready to afford €100 per month, as an example, the subsidy cap is €500, so the rental market prices these apartments to €600 (= 100 + 500). When the state re-evaluate the cap to €550, the rental market goes up to €650. (= 100 + 150)
[1] https://www.insee.fr/fr/statistiques/fichier/1376573/es381-3...
In a market like solar, there is production of more solar systems. There are also multiple readily available substitutes. (e.g. on-grid power) The effect of the subsidy should drive increased volume from manufacturers, keeping net price stable.
For example, you can buy kits on amazon for powering your shed or boat and it's essentially a smaller version of what you would put on your house. No electricians needed. No permits required. Here in Germany you can buy balcony solar kits in the supermarket. They only deliver a few hundred watts of power but it's plug and play. And you can get a nice little subsidy to do that. Some of these kits only cost a couple of hundred euro.
I could see that eventually adding a microgrid to a building is not going to break the bank. Car batteries are much larger than what goes in a house and kwh prices are trending well below 100$/kwh now. Meaning it should not cost tens of thousands to get a couple of tens of kwh to store energy. Inverters shouldn't break the bank either. The going rate for solar panels is around 200$.
Mostly current prices for home setups are much higher than the component cost mainly due to regulations, labor cost, certifications, etc. If you go off grid, you can just DIY and you end up much closer to the component cost. But of course long term both component cost and other cost are coming down. With the exception of labor cost probably. Though the skills needed will become more common and you might be able to do a lot of work yourself.
20× 455 W Canadian Solar panels (~$173 ea)
1× GridBoss MID V2 (~$2 400)
1× FlexBoss 21 (~$2 400)
4× Eco-Worthy 48 V 100 Ah LiFePO₄ batteries (~$1 500 ea)
18 U server rack (~$500) — total hardware ~$14 760
My big hang-up has been the rooftop work, permitting and inspections—almost no one I call will touch a true DIY system. If anyone here in the Bay Area has recommendations for installers or back-of-house permit-whisperers who’ll partner on a non-Tesla/Sunrun job, I’d love to hear how you made it happen. Thanks again for the inspiring guide!
I recently did an Enphase system of a similar size to yours. It was fully DIY except for wiring the combiner and a roofing company to plug all the holes I drilled. Working with PG&E was truly an epic year-plus battle culminating in a CPUC complaint, but in the end it was really just a bunch of emails.
I don't have any installer recommendations, but it should be easy enough to find a local electrician, and I've found that they tend to know others in adjacent fields.
Where you live it’s only 24,000 kWh to pay off the hardware, or just under 3 years ($0.61/kWh). I’d definitely pull the trigger.
magnitude more power from PV than in the winter
That is a tautology.
https://www.amazon.com/NINILADY-Vertical-Generator-Controlle... is a 600-watt-peak wind generator, designed for 11m/s winds, for sale in the US for US$300, presumably much cheaper in countries that aren't descending into kleptocratic tyranny. (I talked to someone who recently bought something similar for US$60. I think it was a 300-watt turbine.) It's a vertical-axis type, less than a meter in diameter. No worries about annoying the neighbors, and it'll probably do a great job of keeping your fridge running most of the time when it's cloudy.
50¢ per peak watt would be a terrible, uncompetitive price if you were a utility company considering how to build a wind farm to sell power for profit. But, if you're a homeowner seeking energy self-sufficiency because your Public Utilities Commission is trying to throw you under the bus because of regulatory capture, it's pretty affordable.
My father has been using wind power in a semi-suburban area in the Uk for close to 20 years now. They have a large wind turbine now but had a much smaller one for a long time. Outside of cookie-cutter estates, there's sufficient tree and building cover that its barely visible to the neighbors. It provides most of their home power.
Democracy really limits governments
(nobody ever describes house prices as a "postcode lottery"!)
Doesn't matter how sensible it is, the other side will use it to score points. I can't believe for a second that Liberal Democrats think that James Dyson or Andrew Lloyd Webber should be able to avoid inheritance tax by buying tens of millions of pounds of farmland, but it's politically beneficial for them to do so.
https://www.gbnews.com/money/energy-bills-rise-postcode-lott...
https://www.independent.co.uk/news/uk/politics/energy-prices...
I also have 60kWh of batteries in my kitchen, but for the average person who doesn’t want to deal with this stuff, having to admin part of the power grid is a tragic waste.
If the PUC and power company weren’t bastards, this could all be in a giant field somewhere staffed by a tiny fraction of the people who have to waste their lives dealing with it in their garages. So many unnecessary struts, so much caulk and EPO switches, so many inverters.
Highly distributed energy lessens the peak demands on the T&D system, which means that the T&D system can be smaller, which greatly reduces the fixed cost of T&D. Utility scale solar requires greatly expanding transmission lines, to the extent that lack of transmission is the biggest barrier to adding solar to the grid in most of the US.
So even if installation costs of solar are higher on the grid edge, it usually makes a ton of sense, and this is evident in the payoff times of NEM3 systems that include batteries. As batteries get cheaper, or there's more vehicle-to-home systems out there, it will only increase.
This lessened need for T&D is the true reason that utilities in California hate solar and need to stop it. They can take a guaranteed rate of profit from anything they get to spend on T&D, but the same isn't true of generation. So utility solar, which requires building more lines and beefing up distribution substations more, lets them profit much more than residential solar.
This solves the T&D problem too, as generation remains distributed.
It’s the money.
Take the Texas ERCOT market, which is the closest thing to a free electricity market that exists in the US. A huge chunk of new grid assets are batteries, becuase they are one of the most profitable things to install right now (see the map at the bottom of the page)
https://www.eia.gov/todayinenergy/detail.php?id=64586
Additionally, many people are now buying EVs, and an EV stores 2-5 days worth of electricity. If big batteries on wheels are commonplace, then simpler and cheaper immobile batteries are pretty easy too.
Even has a name: https://en.wikipedia.org/wiki/Duck_curve
The solution of course is more batteries, but you can't really incentivize non-peak generation until you get the batteries. That's part of the NEM3 change that the blog mentions, to change the incentives from just solar to solar and battery.
Large neighborhood batteries seem to make a lot more sense to me than batteries in every home.
Keeping capacity ready is probably the expensive bit.
Peak demand on most electricity systems, including California's, is during the evening hours, typically between 18:00 and 21:00. This does not coincide with peak solar generation.
You can see this even as far back as 2018 via CalISO's own data. https://www.caiso.com/todays-outlook
Another way of saying that, if we were playing a city simulator as a disembodied beneficent dictator you'd want distributed generation and storage as part of your grid.
In reality there's all sorts of complications, compromises, trade-offs, graft and politics but on balance those factors are working against distributed solar which is succeeding despite them.
Some people have a knee-jerk reaction to anything that requires legislation, regulation or subsidies which clouds the issue though.
You could build fireproof mini storage substations in blocks or subdivisions to load shift, but taking a chunk out of everyone’s garage space and forcing every person to do inverter and battery maintenance is silly.
This is insane. And here I am shutting down nightly the drives in my synology to save 20W.
Another problem I had was that a week after installing, one of the TIGO units burned up and started a fire that burned a hole in a solar panel. I only noticed the problem when I saw that one of the solar arrays wasn't putting out power. Replacing the defective unit solved the problem.
Also, I had assumed I would need a generator to power through consecutive days of dark clouds but I instead opted for Ford's Pro Charger Station which has a feature that allows you to power the house; no need for a generator. However, its been over a year and not once have I needed this.
My big takeaway is this: having energy abundance is the good life when you have all electric appliances. My EV (a Ford Lightning Truck), hot tub, AC, water heaters etc have been running over a year with no problems and zero costs after the initial investment.
Local conditions are typically partly cloudy/rain but still system producing more than can be used.
If all he’s pulling is 1kW I’m jealous.
Networking gear taking that much when it's not busy is really unfortunate. Did IEEE slack on adding effective sleep/downclocking features?
Oxide Computer found that going from tiny 20mm fans to 80mm dropped their chassis power usage bigly: they found a rack full of 1U servers had 25% of its power going to the fans (efficiency is to the cube of the radius).
My whole “rack” draws about 120W total with: aforementioned router, Synology NAS with 4 drives, 2x10G+4x2.5G PoE switch powering a Ubiquiti AP, 16-port 1G switch, and a PowerBook 540c running AppleTalk routing
(I do have an epyc with a bunch of memory and storage, but never bothered doing the math since my UPS claims to be able to run with the average load for 30+mins)
My homelab is between 4 and 8 kW continuously, depending on what I have running. Cooling that homelab is another 400-1000 watts depending on outside air temp.
He mentioned that he refuses downsizing for ideological reasons, and I totally get that, but there's a certain amount of rightsizing that doesn't hurt in practical operation, and still let's you keep what feels like an awesome, big, complex model train setup in your garage.
Not all rust has to spin, almost no ports have to be 10GE, and a lot can be virtualized. Consumer CPUs have much lower idle than old xeons, and having less DIMMs with the same capacity also seems to pay off.
I'd be surprised if he couldn't cut that energy usage to 10% with a clear separation between hot and cold storage, and realistic expectations of bandwidth requirements.
But hey, I'm not judging. Solar power is great, and I don't mind waste as long as he can afford it and it makes him happy. Nobody drives the car they actually need either, and that is a much bigger problem.
I draw 1-1.5kW for my servers in a spare bedroom. It’s not a lot of spindles/cores, just a few dozen.
Your toaster draws 1kW for maybe 5 minutes a day, which is maybe 30kWh per year.
The power in this comparison is not important, it's the total energy consumed (which is what you are billed for in the end).
Odd argument. A cheetah can run up to 110kmh, but that doesn't mean they can cross 110 kilometres in an hour.
Make sure you are buying and not leasing from the company, have that all rolled into a single loan and then you claim the tax credits to help pay for the reroof.
To add to this, they take care of getting the certified roofers, the city permits for both the roof and solar and handle the PTO for you, which from what you called out is even more costs.
No, the smart move here is to find out where the installers buy from, and buy from them. I never explicitly stated I was or wasn’t an installer, they just assumed that I was, as I was buying pallets of panels and kilometres of cabling.
The one advantage of going with a professional installer is that it makes it a lot easier to get grants - I had to spin up a company and invoice myself to get my rebate.
Funnily enough back home along the equator, having a solar setup still is a social signal of luxury!
Mostly I want an easy whole home battery just for some arbitrage. Our rate plan has a 4 hour peak period of $0.27/kwh vs $0.14/kwh off peak. Of course the peak time is when we actually want to use a lot of energy running our AC and other appliances.
Unfortunately I haven't found any DIY stand alone battery systems that offer the simple scheduling I need since most seem to be only backup systems.
But, this is such a cool article. The quotes on solar installs for some reason seem a lot higher than what you'd expect, given all the charts showing the absolute cratering of solar energy prices – but doesn't seem to work out that way when it comes to residential installations.
The author did a very custom setup. If you want to DIY with a pre-integrated setup, you can enroll in Enphase's self installer program, and complete their online coursework:
https://enlighten.enphaseenergy.com/manager/registration?_gl...
I think EcoFlow may have a similar option.
Seeing that somebody has done it is very inspiring, and if I didn't see a high chance of moving in the next 5 years I'd be on it tomorrow.
Well - I say “off grid” but I’ve built a grid - I now have over a km of buried SWA cable linking the three houses on our land, battery banks at each (60kWh of OPzS down at the mill, 15kWh of LiFePO4 at each of the others), and victron inverter-chargers all over the shop. Two arrays of panels each 8kW, one winter optimised, one summer optimised, and planning on adding a third to make more of the morning sun, as we are in a deep and steep valley with awkward topography. Have mucked around with hydro on and off before landing on a plan for an overshot waterwheel using bits of a burned-out ‘88 hilux, which is my current project. Pessimistically it will give us a constant 1.5kW, but theoretically it should end up nearer 3. Either way, that’s a lot of power. Right now I’m stuck running a Honda generator off our biogas in the winter, and it works, but it’s noisy and I have to go yank the cord to start it, usually in the pouring rain.
Using victron and fronius gear all over, frequency shifting to control where the power goes, and home assistant to automate the whole shebang where it’s beyond what the inverters and chargers can do themselves.
As we aren’t grid connected, the permitting process is… “you do what you want”.
It’s all far, far more straightforward than most people think - the hard bit is the physical install, as you’re inevitably lugging awkward panels onto roofs or up cliffs (going for smaller panels can help with this if you’re doing it without any help), or incredibly heavy batteries to wherever they need to be. The lithium arrays weigh about 150kg each, the lead array the better part of 2000kg.
People assume it must have cost hundreds of thousands of euros, but no - all in it has been about €30k, and our ongoing costs are zero.
Out of curiosity, have you ever calculated the cost of the batteries over their expected lifetime ?
Not the detract from the rest of the article, but - it's a company, what did you expect?
Eg basic environmental care/policies or how they handle staff and customers.
In Texas, residential grid-tied solar can be up to 20kWh so I chose cells that got me to 19.96kWh
Then I added an 29kWh battery stacks (18kWh total) but each stack could go to 18kWh (36kWh total). Then I also used a pair of Generac inverters which lets me get two more stacks for 72kWh total.
My goal was resiliency, not sufficiency, so I use it grid-tied so I charge during the day and use at night. When there are storms coming, I flip it to "priority backup" which will prioritize charging.. even using the grid to do it if there's not enough sun.
Anyway, it's been in production since January '22 and my annual* electric bill is ~$1100. Even better, when we have an outage (occasional as we live in a heavily wooded area) if our stack is full, we have ~5 days of battery backup for the fridge, a handful of appliances, and our Starlink.. therefore we have safe food storage, safe food prep, and non-terrestrial communications.
Of course, this cost ~$80k to get there in 2021 (aka before crazy inflation)
A more helpful comparison would be to see your electricity bill before and after.
For comparison, I’m in an area with low electricity rates and I don’t run A/C at the level of someone in a Texas climate. My annual electricity bill is barely higher than yours but I don’t have any solar at all. Absolute electricity bill numbers don’t translate well.
Is there some way to get a better rate by selling CPU time instead, when the sun shines and batteries are full? Especially if you have your own server rack.
I have computing needs that can wait for 12/18 hours. Would it make any sense to have those processed by distributed solar server farms between 11am and 5pm? They just take data in and send results back, using their own "free" marginal kwh.
It would reduce the need the connect to the power grid, but still benefit from selling solar power indirectly.
Cloud providers may just be so much better at doing this already?
Running aircon to burn the excess is better than feeding an already overloaded grid, too. The second best outcome for them, neatly contained in a single euro amount.
As an American I welcome you to our national pastime: burning kWhs on aircon! :P
Even if you are instead in Newfoundland, maybe ask cecooperative.ca if there us a project to create one in your province.
One can imagine a setup where you've got a hot water tank and a mixing valve that allows you to heat your water up to some very high temperature and then mix that down to "safe" hot water for the house. Have that run in "heat from grid if below this threshold, otherwise conditionally heat with surplus energy if the water's below this temperature"
There's a point where the grid has so much solar power that we need to start shedding production as a general rule and not just as an intermittent temporary measure, but I don't think we're anywhere near that point.
This summer I'm building a solar oven to cook bread and veggies with .. and if this works well, I'll build a solar death ray to play with while I wait for lunch.
It seems to me that this is a potential route for the popularization of off-grid/local-energy-harvesting movements to gain more traction. Sure, its nice to have a whole roof full of PV panels and a battery bank to sip juice from now and then, but this still requires a heavy investment in foreign-originated parts and materials.
A solar oven/solar death ray, however, is a lot more feasible to produce locally.
Thanks to California zoning
For actual labor - it's about half days to install roof racks (I have shingle roof so quite a bit of time on angle grinder). Another half day to put panels on (requires 1 or more helpers), run a cable thru roof space. I've installed 12 panels on 2 facia.
My hack was hiring electrician to install inverter so I can export to grid (I'm in New Zealand).
There is a whole cottage industry of DIY 48V 15kWh batteries based on LFP prismatic cells (16x) and special battery case resulting a price of around 1500 Euro for 15 kWh.
A DIY setup is quite doable, Deye (EG4) or Victron make suitable inverters.
The continuous 1 kW power draw I find Ludicrous, probably especially as a European. I would realy rethink what is absolutely necessary. Huge data storage was my hobby but the storage server is only turned on when required, saves a lot of power.
Waiting for government, my kids currently in primary school would probably have graduated from college before they fix the power situation (they are currently fixated on building roads to nowhere).
Wow. That's ten years of electrical bills where I live in Texas, and you also have to deal with the increased water leakage risks, any maintenance issues, storm problems, etc.
I got dinged for this on the first inspection of my own self-installed solar+battery system.
A lot of signage companies don't know how to do the placard, but the company that I found that knows how was PVLabels:
The total outlay in that calc is affected by how big of a system you need though.
If you've got no obviously inefficient gear then yes you just put in a system of whatever size is needed.
If you have easy wins on the consumption side then you do that first.
Silly example but say you could eliminate half your consumption with a once off $100 spend then you do that. You don't pay through your nose for an system twice the size just because of ""free"" power later.
Where that cutoff point lies will require calculation, but chances are old enterprise racks are on the wrong side of it.
The big benefit is the resilience. Since you are using them every day, they will be far more likely to work in the event of an outage than a gasoline generator that you test once a year.
There are benefits to being in the bay area, too. This happens to not be one of them.
Living in "a part of the country that has basements" is no utopia either.
Also: my house, in the bay area... has a basement.
There are plenty of more efficient ways of doing things, but I still stuck solar on this old, energy inefficient house.
Giving up one foot of space along one garage wall is not a big deal. And if you're worried about physically getting the batteries into place, hiring people would still be cheaper than movers.
Also, a basement that removes cooling costs for the home lab would not make a big difference. If the 800W A/C unit runs 8 hours a day for 4 months out of the year, then it's only about 10% of the home lab power use. Since it's not needed at night it's probably even less.
And not a cosmic solar system.