That $300 worth of electricity for the year is before I've been able to talk the wife in to replacing our incandescent bulbs, swapped out our old pool pump, etc etc - I could easily get that down to below 0 with a small investment in bulbs. So in my case at least, it was trivially easy to get to a net-zero usage.
A few $$ notes - the system cost $37k, I got 11.1k of that in a tax credit from the feds, so my net cost was 26k. I'm saving 5.7k/yr, which means my break even point for the system is 5 years. In 5 freaking years I'm making money from my solar panels! And I don't have to write a $500 check to PG&E every month. It's a beautiful thing...
BTW - the above numbers (plus my severe aversion to debt) are why I'm so against solar leases. If we had a solar lease, we'd still be stuck with monthly payments, would have trouble selling our house, and would be stuck for 20 years.
I get irritable if my bill hits $250, I'd be freaking out at an average of $500/month.
The have so regulated pricing and punitive structures into service there that they have to have assistance programs just to alleviate the burden on middle income and lower consumers.
Where I live, in SW Missouri, capital and maintenance costs might be higher due to weather (e.g. high winds, hail), and it would be useful during the summer---which the electric company would be generally thankful for, less $$$ peaking power needed---but much less so in fall and winter when it's frequently overcast.
Also, if you live in a place with high electricity rates, like California, the case elsewhere is less compelling. I probably pay on the order of 1/2 of your savings for the total power to handle a building that's almost certainly bigger and thirstier than your's (numbers on request).
Our AC and pool pump are big parts of that $6k/year usage, and while AC is a luxury, when it's 105* for a week or two straight and you've got little kids around, it sure is nice.
There are also 2 other factors that feed in to our electrical costs - I work from home, and we have 2 little kids. That means our home doesn't get to shut down during the day. AC, fridge door opening, lights, etc., it all adds up when 4 people live in a house 24/7 instead of being gone during the hottest parts of the day.
$400/month electric bill, very typical for summer.
Northern Illinois has extremely cheap power due to Exelon's nuclear generation capacity (Ameren in downstate us primarily coal-fired). I expect the price in IL from ComEd direct to start going up, as they're going to use their smart meter rollout to start pushing time of day metering (as they should) vs flat rate per kwh pricing.
Someone paying $5,000 a year for electric has strong incentives to make improvements, so I was wondering about the specifics, not trying to make a brilliant suggestion that all they need to do is put up some pink foam.
I'm in the bay area just replaced my furnace, water heater, and insulated ducts (an 11k job), and I'm expecting a $2800 rebate from the BayREN program (the local program that implements Energy Upgrade California).
Once every few months the monitoring doohickey needs a reboot, but the panels work with or without that.
For my personal situation, unless PG&E reduces their power rates over the next 5 years, I'll absolutely hit that break-even point.
Panel production will degrade over time - the warranty covers something like 3% the first year, and 1% every year after that. So at 5 years I will have less than an 8% reduction in output from the panels. That 8% will be made up by that time with LED bulbs, a variable speed pool pump, etc. Heck, right now out of the ~30 ceiling cans in my house, only my office (4) and front porch (3) are LED. The rest are full 60W sucking incandescent bulbs. The chandeliers are also 60W bulbs too, accounting for another dozen or so lights that are on quite frequently.
What can I say - my wife hates CFLs and barely tolerates LEDs.
I haven't looked into the ROI of CFLs or LEDs vs. incandescents in a while. I imagine they have improved. Lately, I've even seen some LED bulbs in stores that don't look horrible. Of course, I would buy them anyway just to save time changing bulbs!
Maybe you could slowly transition... replace one bulb a week over the span of a year and she may not even notice :)
The cost of maintaining all of the power infrastructure for a region is relatively fixed, especially if people don't disconnect completely when they add renewables. This cost is generally recouped by a small surcharge to every kWh that's provided to customers. The possibility of a spiral arises when customers start purchasing significantly less power from the utility, which means the per-kWh cost for the remaining customers will have to increase. As this cost increases, the ROI of adding solar panels improves, so more people add solar. As more people add solar, the utility must increase prices to the remaining customers.. etc. etc.
There's also pressure on this spiral from solar installers since the 'soft costs' make up the majority of new installations. As more people purchase systems, the per-installation price will decrease due to installers getting bulk discounts for materials, efficiencies (physical and bureaucratic - dealing with permits, etc.) from previous experience, and a bigger base to spread out the costs of their own capital equipment.
Detractors think that utilities are fear-mongering to increase their operating and price flexibility, which would likely result in higher profits in the near-term. I don't think I buy this theory though, looking at my last bill of about $50, $28 was generation and about $25 was transmission & distribution (T&Ds). PG&E bills T&Ds based on system costs / proportional usage, so if I cut my power, my T&Ds would drop to almost 0, increasing the cost on everyone else.
Here's a pretty balanced article about the issue;
http://www.renewableenergyworld.com/rea/news/article/2014/04...
An ideal world for a utility would be one where everyone used a moderate amount of energy at all times. The reality though, is that peak consumption is typically 100% higher than the night-time lows. An example from a utility;
http://i.imgur.com/gPR7DNk.png
Most of the efficiency programs are targeted at lowering that daytime peak. You would need less overall generation (saving money on building new power plants) and have a much more stable system if you could flatten that whole curve.
Their ideal is for power usage to remain exactly constant, or at least grow at a constant pace that matches local realities. The population and their power use wants to grow faster than that. Efficiency helps to compensate for that.
You'll also note that a lot of the efficiency tips are aimed at peak consumption. That's not the case for light bulbs, but there's a lot of stuff around more efficient air conditioning. Peak power is much more expensive than average, and in many places the power company can't charge residential users accordingly. Air conditioners tend to be used at peak usage times, so decreasing that peak usage can save them a lot of money.
1. It is highly dependent on the amount of sunlight an area gets. This might seem obvious, but is also problematic in that it is difficult to build the correct capacity for climates that vary significantly over seasons. Solar is well and good in Los Angeles, since the weather is very consistent, and the amount of sunlight doesn't vary hugely over the year. In Seattle though, if you were to install enough capacity to be useful in the winter, you would drastically over-produce in the summer. Over production of solar is currently a problem, and can have significant detrimental impact on the overall power grid. Typically, when it drastically over-produces, it can cause blackouts. This is amplified by the fact that solar produces its maximum amount of output at a time when people don't consume the most electricity. This may eventually be mitigated by better batteries, and alternative power storage systems like Vanadium Flow systems.
2. Solar has a maximum capacity, and will likely always need to be mixed with other "on-demand" power generation systems. At present, these are Coal or NatGas generation stations that can be ramped up to meet spikes in demand. Effectively, these plants allow us to store energy chemically in the gas/coal and burn it on demand. very few renewable energy sources have the ability to be ramped up to greater production over short period of time. Again, this problem could be mitigated by substantial battery installations, where a small amount of excess generation from solar could charge batteries that could be drawn on to deal with spikes in demand.
3. Power transmission is always going to be a problem. Solar is less and less viable the further toward the poles you go. Though we could generate power in the southwest, there are practical limits to how far power can be transmitted over existing lines without too much loss.
In all, though it would be possible for Solar to operate a given house or building with on-site generation. It is very unlikely to threaten the power companies, which give us a low-cost, reliable, and simple solution that is capable of meeting our needs.
Many/Most systems I have seen in southern California contribute energy to the grid directly, and power is still purchased through the grid like normal. When your panel is generating, the power you generate and consume balance out and your power is "free", but you don't consume power straight from your panel (a flawed representation of how electric flows, I know).
The challenge with these implementations are that the grid itself handles the power generated by panels, and can't turn them off. The reason they do the installations this way is so homeowners stay connected to the grid to even out their energy spikes, but also to save the homeowner the cost of battery storage systems. In this case, the grid acts as "storage" by accounting, rather than by real storage of energy.
My utility has been pushing a thermostat that they provide at no cost and will even give you a bit of cash for installing. The reason is that this thermostat is hooked up to the utility through the internet and can be shut off by them during a spike or an emergency.
I just got new smart electric meters installed too.
If those meters were a little bit smarter, connected over the net, and had the ability to restrict flow ... they could easily install devices on a per house basis that would protect the grid. That would put the ball back in the homeowners court and the homeowner can implement a solution to shut off the panels when the utility isn't interested in purchasing power back.
This is a pretty regionalistic viewpoint - in many parts of the world the peak solar production and peak electrical usage are highly correlated due to air conditioning use.
Pumping workloads (AC, Refrigeration) are fairly static loads on the grid though and don't account for very much (~7%) of the overall energy consumption (http://www.eia.gov/consumption/residential/).
The trouble with solar only really happens when their are spikes, either in over production, or over consumption.
Most people are away from home during the day while their battery charges and then come home for a few hours at night when the battery powers the house.
Now, there are certainly cases, perhaps even many of them, where it wouldn't really work out. But for me it's the ideal setup. My wife and I live in a 1300ft2 house and use 250ish kwh a month in electricity including recharging an electric car a couple times a week. A 1.6 kwh system would cover almost all of our energy needs. Couple that to battery storage so we could use the energy we generate during the day when we are at home at night? Perfect!
it is still daytime, but typically not peak solar hours.
it is this setup in particular that is problematic for spikes in generation, since the power company can't just disconnect your solar array if it is adding too much power at a low demand time.
Increasing generation capacity to meet demand spikes is expensive, and requires having large, expensive power stations waiting at the ready, just costing money.
http://www.eia.gov/forecasts/aeo/electricity_generation.cfm
The interesting bit here is how wind is already cheaper than any other option save combined cycle natural gas, and wind is on track to surpass natural gas.
The idea is that the sun heats up the ground. When the wind starts moving, it goes up the chute, spinning the blades.
It was theorized that a 1mile diameter ground cover + tower would give 500 MW of power.
* Typical efficiency of a consumer solar panel to day is about 12%
* Average of 6 hours of sunlight a day over a year, sunlight providing 120 W/m^2 [1]
* Rooftop of about 80 m^2
Total energy over a year comes out to about 2500 kWh.[2] Apparently the average household energy usage in the US is about 10000 kWh[3], which would imply that you could get about a quarter of your energy from solar.
A few caveats:
* Apparently some places get up to 2200 kWh/m^2 per year of sunlight[4], which would bring your solar panel total to about 21000 kWh a year.
* Not entirely sure how big your average rooftop is.
* Solar panels have been created with efficiency in the 40s of percent[5]
Hopefully I'm not completely off with some of these, but it seems reasonable that a rooftop system can provide most or all of your power in the near future, depending on how sunny it is where you live. If it's not sunny, you might have a lot more problems, though.
[1] According to https://en.wikipedia.org/wiki/Sunlight, the World Meteorological Organization defines sunshine as a state of receiving at least 120 W/m^2
[2] http://www.wolframalpha.com/input/?i=365+days%2Fyear+*+6+hou...
[3] http://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3
[4] http://www.nrel.gov/gis/images/map_pv_national_lo-res.jpg
[5] http://www.sciencedaily.com/releases/2013/09/130923204214.ht...
http://en.wikipedia.org/wiki/Insolation#Earth.27s_insolation
(the 250 W/m^2 there is the 24 hour average)
>> Ignoring clouds, the daily average irradiance for the Earth is approximately 250 W/m2
Emphasis added. Seems like clouds might be a non-trivial factor, yes?
(The difference between the values is ~8x, I doubt clouds have that big an impact in very many locations)
His ROI in 5 years but can possibly be less. Depending on the state/market/utility, the owner qualifies for local rebate incentive, homeowner solar water heating rebates, local labor substantability rebates and SRECs. SRECS are energy credits that are similar to forwards contracts that can be traded on an exchange. The federal tax credit (ITC) is 30% of the purchase price but expires in 2017 to 10%. But, forecasted solar cost drop to 2017 would far cover the itc.
Additionally, the Total Cost of Ownership of Solar will be higher in areas where panels/solar systems are prone to damage from weather etc. Wind, Rain, Snow, freeze/thaw, dust can all damage solar arrays, or negatively impact their performance.
If there are batteries involved, those will likely also need to be replaced before the system has initially paid itself off. Even if batteries get cheaper and better every year, the disposal fees for old batteries and their current inability to deal with house-sized loads well can easily add significant cost.
I don't want this to sound like I am anti-solar. I am a big proponent of solar, but there are many problems with the current system. It is a somewhat unfair comparison no matter what, since the energy we buy from fossil fuel generation does not accurately reflect the cost of the pollution it makes or the environmental harm it does.
True, without the 11k rebate, my break-even point would have been 7 years instead of 5. I'd still have done it...
Depending on whether you sell your house or not, I assume that the solar system will also generate a reasonably high ROI as an improvement to the home? It would be interesting to see what the real payback time period would be if you were to try to sell the house before its usage ROI were realized.
i.e. could you buy a house, add solar, get the rebate, sell the house after 2 years and still get a return on the solar investment money because you'd improved the value of the house?
http://www.livescience.com/4824-solar-power-rule-20-years-fu...
According to that article, he said the "use" of solar energy doubles every two years.
Efficiency has been gradually improving, but it's definitely not doubling every two years. Every few decades would be closer; that said, using an exponential curve to model a function that's capped at 100% doesn't really make much sense in the first place.
http://www.eei.org/ourissues/finance/Documents/disruptivecha...
On the other hand, cities don't have the surface area to account for industrial consumption.