Co-ops to make residential solar more economical
I never thought too much about solar until my recent trip to Florida. We’re planning to get solar on our roof, but largely to create some energy independence and wean off the natural gas our municipal electrical company uses. I’ve been bullish on solar, especially as its cost drops and adoption increases. But I’ve also thought of it as a sort of incremental or bonus energy source – something to supplement fission (and hopefully one day fusion).
But recently I got a bad sunburn in Florida, the kind that makes warm showers painful and clothing choices important. I got sunburned by walking along the beach with my son over about 30 minutes (he had plenty of sunscreen). As we were driving to the airport a few days later – sunburn still burning – I looked out at an empty parking lot that was about the size of a football field. I occupy about 2.25 ft^2 when standing. I realized I could have been standing anywhere in that parking lot for 30 minutes and would have been burned. I looked at a small invisible square in one empty parking spot, then at an adjacent square in the same parking spot, then another, and finally to the edge where it abutted the next parking spot. Standing in any one of those squares – there are thousands in that one parking lot – for 30 minutes would have given me the same sunburn.
It’s astounding to think of the amount of energy bombarding the earth anywhere the sun shines. This is technically obvious – anyone who has heard of Dyson spheres or kardyshev levels has realized at a rational level the immense power of the sun. But once I visualized that parking lot, I started to internalize this as an incredible force that we are squandering.
For the rest of the drive to the airport, I obnoxiously pointed out to my wife (not *trying* to be obnoxious – there’s a difference when you’re a husband) all the places where there could have been solar – above parking lots and strip malls, in fields of drying grass – and the places where I actually saw solar fields (a much smaller number). But every rooftop and parking spot was a painful reminder of the wasted opportunity.
When we got estimates for rooftop solar at our house, my wife and I were somewhat shocked. I’d been told the cost of solar panels was decreasing every year, but there was very little evidence to support that in the estimate we received. For sure there is some predatory market for well-off liberals looking to virtue signal by putting solar on their roof. And I’m sure there are other costs that haven’t scaled the same way when it comes to inverters and grid connections – after all, the US energy grid was not built to be decentralized. There are further issues associated with permitting and labor that all go into the final number. But that number is too much.
About 6 months ago I contacted a few solar companies to ask how much it would be to build a system that could generate what my house needed – about 200 kWh/week. It’s telling that the first thing all of these companies asked was how much I currently pay. What does that have to do with the system cost? They knew where I lived (sun strength and geometry, seasonality, etc) and what power I roughly needed… but they also know their costs are too high and so must be framed in terms of pay-off. Even those numbers are poor since you start butting up against the efficiency decline of the panels versus manufacturer guarantees.
This lead me to my first practical realization regarding solar: Given the costs of solar, is my solar piggy bank really best deployed in Massachusetts? Wouldn’t it go much further in Florida, or Texas? I don’t own any land there, but maybe I could find cheap land *somewhere* that would be a good site. It wouldn’t defray my power consumption at the meter, but if I could sell it back to the grid it would provide some revenue to set against the investment.
Second, are there economies of scale that disproportionately favor larger solar projects? If I buy an inverter for my little roof system, how much more would that component cost if it were to handle 2x or 10x the system load? What I bought one with spare capacity so each year as panels get cheaper we can slot them in, staggering effenciency decreases over time (instead of failing around the same time). Wouldn’t a better approach be to build these optimized solar blocks with investment from people who are interested in putting it on their roof to help them get more from their investment (and thereby produce more clean energy)? Such solar co-ops could be extremely efficient uses of capital and energy generation. It would resemble buying a “carbon credit,” but one that provided almost immediate return on investment dividends and spread risk or failure and inefficiency over the aggregate.