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Comment by sxates | Hacker News Reader

Personal anecdote - my house has two sets of solar panels on the roof - the first was installed in 2017, the second was just installed last month.

In 2017 my 6kw system cost $24,000 before any incentives (by SolarCity).

In 2020 my 7.8kw system cost $15,000 before any incentives (by Tesla).

Of that $15k, $4.3k was for the panels themselves, $2k for the inverter, $1k for mounting hardware, and $8k for installation.

It's pretty shocking to me that in just 3 years the price per watt was basically halved, all in. Because looking at the breakdown, half the cost is in installation and presumably marketing and sales costs. Even if the panels themselves cost half as much, it would be a relatively small decrease in the total cost of the system.

I wonder what the practical bottom is - even if the panels were free, there's a floor on the labor cost.

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From my perspective those costs are massive. I'm considering building a whole house from bricks which will cost $30-$40k. I probably won't spend $15k for electricity for all of my life. I don't understand western economy. You've got extremely costly electricity and you're claiming that solar power is good. It might be true for you, but it won't ever come to me at those prices. I'm paying $0.03 for kW⋅h. I'm spending around 200 kW⋅h per month, so that's $6 per month. I would need to live 208 years to save $15k.

Solar panels might be fine in some distant places where you're forced to use diesel generators. Diesel is not cheap. But where electrical grid is already in place, I just don't see it working.

The average cost of residential electricity in the US is just under $0.12/kWh. A $6/mo electricity bill is pretty much unheard of around here. My electricity bill is around $50/mo and we only have 2 people living in the house. It would still take me ~25 years at my current rates and usages to break even, but the economics might work out better if you have a higher occupancy residence.

I think energy companies factor in distribution costs and a bunch of other costs beyond pure energy cost per kWh, hence the hefty price.

As more people move to electric vehicles putting in solar panels will become more feasible. The price of solar is falling so fast that if it is unfeasible today it might not be the same 2-4-6 years from now. 5-6 years ago a lot of people that are installing solar now calculated that it was not worth it for them then but it is now as the prices have fallen 50-60%.

It's impossible to charge electric vehicles on solar panels. You charge at night when the panels don't produce and the panels don't have enough capacity to charge the vehicle completely. So you need huge batteries that will be even more expensive.

Battery prices are also falling 18-20% every 2 years a tesla powerwall costs around $7k now $11k with installation. You dont need to top up your electric vehicle 100Kwh every night looking at avg car use most people would need to top up 7-8Kwh only so the battery cost wont be extremely expensive no need to install 100Kwh battries just 12-15Kwh would be enough.

7 to 8 Kwh is already more than half the production of an average standalone house. Which means that the rest of the house has to somehow do without half it's production.

Also, outside of cost, batteries and solar panels have a huge environment cost during production and are still terribly difficult to recycle.

Windmill blades are often buried underground for example.

Where do you live that you pay $0.03/kWh?

A lot of bitcoin miners would love that rate!

Kazakhstan.

Interesting. I looked it up and that sounds about right for domestic users.

The cost of solar in the US is highly dependent on labor costs and the regulatory process. So OPs system would cost less in Kazakhstan based on lower labor costs.

Residential solar is also an expensive way to produce solar. In the US we have industrial scale plants that produce at $0.018-0.024/kWh.

According to:

https://www.iea.org/reports/kazakhstan-energy-profile

Coal fuels around 70% of electricity generation (in 2018), followed by natural gas (20% in 2018).

(rest seems to be hydro)

I assume cheap because no carbon tax.

I live in India where equation is similar. Power is cheap.

But when I factor in power outage which happens a lot, the solar is much better deal.

I've had 24/7 power sine we moved to solar.

> I probably won't spend $15k for electricity for all of my life

Living in a two bedroom unit in Sydney my last quarterly electricity bill was over $500.00 which comes to over $2000.00 a year.

Basically here in Sydney we have high electricity prices and my washer, drier and air conditioner love to chew up electricity.

Where does the heat of you drier go? Into the room to be moved again by the air conditioner, or directly to the outside?

I'm not the person you replied to, but dryers are typically vented outside.

But you have to factor in that the majority of the cost is installation. I’m going to bet that labor cost in your country isn’t nowhere the cost of that. If the labor cost in your country was the same as the US then your current power cost would be that low either.

The installation cost is probably cheaper in your country so I will ignore it.

Assuming a 16% capacity factor that system will generate $328 worth of electricity a year at $0.03 per kWh. It would break even after 22 years. That's incredibly far away from the 208 years you have quoted.

The flaw in your thinking is that this setup wasn't chosen for you. It wasn't build in your country nor was it built by you so why would you compare it to your own needs? If you had to build your own solar system you would get a smaller one (which would decrease the breakeven duration according to your weird criteria despite not meaningfully changing the system) and you would probably install it yourself.

The reality is that wherever that solar system was built electricity costs more than $0.03 and the person needs more energy or feeds the the energy into the grid.

It's like complaining about a family of five getting a Volkswagen Sharan when you are just fine in your Citroen Ami. It's not about you.

You seems to have very cheap energy, here in Poland it's ~0.1$ but coupled with ability to store excess to grid it's quite practical and there's big rush with people installing solar panels. As you can use this extra elecricity for heating in winter which typically is 500$ to $1K per year (coal vs gas) + 500$ for elecricity per year, this means it pays for itself quite fast (not installed it yet for myself, want to be proven on durability of panels). If you don't have heating/AC need then it's probably less economical yet.

Building house here also starts around $50K (not counting land price). BTW land prices rose from 500$ to $500K on nice terrain when asphalt roads where build (in like 15 years span). I am happy that solar panels + storage are getting cheaper as building house anywhere will become possibile. Probably will contribute to faster development of poorer countries/regions with bad infrastructure.

I'll add some anecdata from Australia.

My neighbour had a 5kW system put on, single-phase inverter, about three years ago - for ~ A$7000.

I've just put a deposit down for installation of 12kW of panels with a 10kW three-phase inverter for A$7400

Same provider, though I haven't compared breakdown of costs (I'm assuming very similar installation / labour costs).

How do you find a provider? Feel like sharing who you used and some details?

I'm not sure where you are, and what regions the vendor I'm using covers, but I did pick Beyond Solar.

This was mostly because my neighbour, an ex-power plant engineer, with much more expertise in this tech than me, had selected them three years ago, and his son had gone through a similar process a month or so ago and also chose them.

Quality of the equipment is the big factor, and I gather a lot of the significantly cheaper companies are cutting costs on the quality and/or warranty.

I was recommended https://www.solarquotes.com.au/ by several trusted sources for comparing options, though didn't end up using them.

Thanks!

I wonder how the economics on this work. Does it make more sense to wait or does it make more sense to buy at any point since you always win?

Good question. In my case we're spending an inordinate amount on power currently, because we're using upwards of 20kW / day. Part of that is a horribly inefficient hot water system, part of it is needing an air conditioner this time of year (here in Australia).

The new system will include a smart meter changeover, which means hot water can be off-peak, and time-constrained, and air-conditioner will be used primarily during the times that we're generating power.

Combined with some other plans - adding a shade-roof over one of the existing poorly insulated structures, replacing the HWS with a heat pump, etc - I expect that we'll be close to power-positive most sunny summer days when we're on-site, and every non-cloudy day that we're not.

Payback for my neighbour was ~ 3 years, though he was more extravagant with his air conditioner because it wasn't costing him anything to put it on. I expect a similar or slightly faster payback period.

In which case - it makes more sense for me to do this immediately. Whether it would have been the case 3 years ago, I'm not so sure.

Coming at this late, but that is a really good price for a fully installed system, does that include some government subsidy?

Considering a similar system like that in southern Europe where installation is pretty cheap, and the prices are higher, I see A$12000 for a 10KW system of panels and a 10KW Fronius three-phase inverter.

Yes, there's some rebates from federal government in those numbers.

For the record:

33 x 370W solar panels (Jinko) - 12 year warranty

Three-phase inverter (Sungrow), battery capable down the track

Installation (labour, mounting kits, wiring, etc)

Total is A$13,000 -- less the government incentives / subsidy ($36 / STC) of A$6,600 which are intercepted by the vendor in this case.

In Australia these subsidies are taking yet another hit at the end of this year, hence there's a bit of a spike in people paying for these systems, but scheduling installation in 2021.

The more installs done, the lower labor can get as everything is streamlined. A whole roof can be replaced for less in labor- which is coincidentally a much larger market than panels.

How much savings/profit do these actually generate to you? I guess some quite significant numbers, if you decided to actually expand capacity.

I hear more and more that building codes are updated to include solar. So maybe there will be a standard, thus reduced cost.

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