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by ramesh31 8 days ago
>I installed a solar system at my home in Massachusetts for 17k last year (after tax credits), 7.82 kw.

This is the problem still in the US. Even at ~$0.23/kwh delivered in the northeast, you're looking at an ROI of nearly five years. Fine if you can float that kind of cash to feel better about yourself, but the economics just aren't there for most people, especially in cheaper parts of the country where rates are ~$0.12. Even financing you're looking at a monthly payment equal to or greater than an electric bill. Of course if you have the time to amortize it you'll come out ahead, but there's simply no cheap solution that can actually save real money out of pocket in any reasonable amount of time beyond theoretical future savings on paper. It will never be a true solution without massive subsidisation that reduces out of pocket to a 1-2 year horizon.

6 comments

This perspective is always so myopic to me. I say this as someone who doesn't make much money who's in the middle of a massive solar install (DIY). I made some simulations and a spreadsheet to work out all of the scenarios and I figured out that with a loan I can come out at monthly financing costs nearly exactly my electrical bill every month. That's right, I can have a 12 kWh battery backed 18 kW whole-home installation at no additional monthly cost.

The way that these discussions get contorted online will never make sense to me. The same people who make comments about ROI and it not making financial sense also have new car-loans on vehicles that depreciate catastrophically and are worth nearly nothing in 10 years. After 10 years my solar install will have been paid off for three years, I will get free electricity, and I will have the following benefits along the way:

Additional home value/equity

Backup power in case of grid problems or catastrophe.

Free fuel for my used battery electric vehicle. (compared to ~$200 a month in gas)

As close to zero carbon footprint as you can have in our contemporary world

And that's all assuming electricity prices stay the same. That's not even talking about how hydrocarbons are a very finite resource. Saying there's no "ROI" is looking at the situation like the only variable is your monthly expenses. It's the best decision anyone with a home who has the climate can possibly make. If you value your independence and personal security you'd be crazy to not do it. What would you pay, if you have the kind of money most people on these forums do, to ensure your home operates independent of external inputs? Imagine a new great depression? Or other such event?

>"Saying there's no "ROI" is looking at the situation like the only variable is your monthly expenses."

That's the reality of life for most people outside of our little bubble of six figure earners. If it's a higher monthly price, it's a nonstarter.

>"Additional home value/equity"

I wouldn't be so sure of that. Solar is a massive maintenance liability that a majority of buyers will avoid. Fine if you find the right one willing to pay a premium, but how much more are they going to pay for an old system vs. installing their own?

I'm not a six figure earner, and have never been close. Your mentality is not everyone's mentality. And there are many people, my neighbors and friends, who are willing to pay more for energy security and independence who are not in a bubble of six figure earners.

For your equity comment, it reads like astroturfing. Every single report with real-world data shows that it's positive equity and that homes with installations sell for more than those without. It's not a "vibe" I have, it's a cold hard fact. There's a million things you maintain when you own a house, and free energy is literally the easiest thing to want to maintain. Compare that to siding, or septic, or anything else....

Your comments aren't in good faith at all.

> Solar is a massive maintenance liability that a majority of buyers will avoid

My parents put up solar in 2005 when it was very expensive. The original panels, inverters, cables are all still there, nothing had to be replaced in the last 21 years. The only maintenance task is a recommended (not mandatory) yearly cleaning that is probably in the 300€ range and takes maybe 1h, but since 5 years they have 2x EVs and 2x Powerwalls and are self-sufficient for 80% of the year, so that cost is negligible. The area where they live also has enough rain that if they skip cleaning for 1 or 2 years, the average total output is still close to the max they can get.

> massive maintenance

What maintenance for solar panels? Please share your videos of oil changes on your solar panels.

As opposed to equipment for fossil fuel which (a) doesn't burn fuel (b) has no moving parts (c) doesn't have thousands of parts and therefore runs free of any maintenance forever?

I wonder where these kind of people come from and what kind of education they have? Even Pakistan seems far more technologically advanced, they've been rapidly deploying solar with no issues.

> Solar is a massive maintenance liability that a majority of buyers will avoid.

That's not at all true where I live (Seattle): the cost of a solar system goes almost straight over into home equity. Solar energy is a feature - a real selling point. No idea what maintenance liability you could have in mind; one can have panels cleaned once a year, for maximum output, but they still just work if you don't. Other than that there is literally nothing to maintain.

> Solar is a massive maintenance liability

... Wait, which maintenance is this? You'll probably eventually have to replace the inverter (or, at least, solar panel warranties are normally considerably longer than inverter warranties), but that's probably about it.

(Theoretically you can get a minor efficiency improvement by cleaning them regularly, but it really is minor to the point of "arguably not worth doing at all" in most conditions.)

> Solar is a massive maintenance liability

Can you cite sources please.

I’ve had my system in Canada for 2.5 years, flawless, not one second of maintenance.

Family in Australia have had systems for over 10 years with zero maintenance

Also electricity here is ore approved to increase by a minimum of 5% a year, so a solar install on a house is huge for equity. Most people here spend around $2k to $3k a year on heat. I spend $400.

A 5 year ROI on a system that should last at least 20 years isn't an investment to feel better about yourself. It's a way to save money.

Three years ago, I was paying about $0.12/kWh, now it's about $0.22/kWh and installing a system makes sense.

It's cash up front for a savings later. My roof was due for replacement 'soon' but not immediately, and I didn't model the cost of moving that 3-5 years from the future to the present.

If you can't manage a 5 year planning horizon on a house, I'm not sure that home ownership is a great idea.

I get it if the ROI is 10+ years... too much uncertainty to put a lot of capital in.

Is a 5 year ROI really that crazy? Seems very reasonable considering lifespan of solar is more like 15-20 years (or more).
Mine are guaranteed to output 80% of their rating after 25 years.

In the real world panels that old are putting out 85%

> Fine if you can float that kind of cash to feel better about yourself,

Why do you need to float cash? Thats your assumption.

> you're looking at an ROI of nearly five years. Fine if you can float that kind of cash to feel better about yourself,

Huh? 5 years to ROI, _after which you get free energy for the next 20 years_, seems like a pretty good investment.

> Of course if you have the time to amortize it you'll come out ahead, but there's simply no cheap solution that can actually save real money out of pocket in any reasonable amount of time beyond theoretical future savings on paper.

I, ah, disagree that five years is not a reasonable amount of time.

getting your money back in 5 years is pretty good, or am I missing something?

That's 15% yearly

That 5 years assumes you can provide 100% of your electricity usage via solar, which is a complete fantasy outside the south/southwest US, and would realistically require a >10kw system. But again, it's also the out of pocket money we're talking about. Very few normal people can float that, and opportunity cost is real.
Why do you need to assume 100% generation???

It's all about the all-in cost of the system vs the reduction in utility bill.

If your system runs 20% of your usage, it still has whatever ROI it has.

Building to cover 100% usage isn't a typical goal if you're planning to keep the utility anyway. Most net metering doesn't pay you if you make more than you use, so if you go over, you spent too much on your system.

>Why do you need to assume 100% generation

For the time to payback to be even remotely close to 5 years in that scenario. Otherwise you're easily talking a decade plus.

That makes no sense whatsoever. Thought experiment:

Household #1 uses 7 kWh of electricity per day. They install a solar + battery system that produces 7 kWh per day, covering 100% of their use. This costs them $C, and the reduction in the amount of electricity they use from the grid will save them enough to break even in 5 years.

Household #2 uses 14 kWh of electricity per day. They also install a solar + battery system that produces 7 kWh per day, which covers 50% of their use. This costs them $C, and reduces the amount of electricity they use from the grid by 7 kWh per day, just like household #1. Therefore it should take them 5 years to break even, just like household #1.

Breakeven time is a function of cost and the amount your grid usage goes down. How much electricity from the grid you use if your solar system cannot supply 100% of your usage should be irrelevant to the payback time.

I don't get it... system costs scale pretty closely with number of panels.

If a $X system covers 100% of your use, a $X/2 system probably covers 50% of your use.

Ignoring time value of money, if the $X system saves you $X / 5 per year, the $X / 2 system that generates 50% will save you $X / 10 per year. Both systems would have a 5 year ROI.

Even if your half price system generates only 45%, it only brings the ROI out to 5 years 6 months.

There's are some fixed costs to hook into your panel and whatnot, but as long as your system is within a reasonable range, the math should math pretty well until your system generates more than your usage. Assuming the math maths at all... if system costs are high and utility rates are low, it doesn't math. If you roll a roof replacement into your system cost, then yeah, a small system won't get you the ROI, but I don't think the math works to include roofing in the system cost unless your utility power is very expensive per kWh. If you're in a reasonable cost area, and you need a new roof for your system, you need to wait until it's time for a new roof anyway. Or if you can't afford a new roof and a solar system at the same time and don't want to finance the solar system, you could probably have the roofers put in rails for future panels when the roof is installed so that the roof warranty covers the rails. Then you can add solar when you've rebuilt your reserves.

>"Ignoring time value of money"

The time value of money is the entire point of what I've said.

And it goes up exponentially when you are just getting by as most of us are. $17k right now is worth incredibly more to me than saving $200/month for the next 20 years.

Identical solar panels in San Diego produce more KWh than they do in Boston. Same cost, quicker payoff.