Currently solar economics are driven by “net-metering” policies. Briefly, you are allowed to deduct generated electrons from your power bill. Thus, depending on your usage, there is a limit to how much solar you can get paid for generating. Some say that is fair, as sometimes excess electrons cause more problems on the grid. Nevertheless, policymakers are missing a bargain, as it might be far cheaper to oversize my solar array than invest in power generation elsewhere. That marginal cost, might be quite cheap.
About $3/W is a common number when googling “how much does solar cost” in Ontario (source and source). But looking at just the panels themselves, one vendor has a 400 W panel for almost $100, why that’s only 0.25 $/W (source). This suggests that most of the cost of solar is in the installation and permitting, with the panels themselves being a relatively minor expense. If my googling holds up, why the panels themselves are less than 10% of the overall project.
And there is the opportunity, why not permit over-sizing of the solar array? If costs are mostly in the installation and permitting, chances are adding a few extra panels would not cost all that much extra.
Here in Toronto, my utility, Toronto Hydro, has a slightly simpler process, if export is limited to 10kW (source). For a variety of reasons, I am actually considering a solar array a bit above 10kW, my house is likely to use at least 1 kW, and then my home battery system can charger right of the panels, allowing perhaps as much as 15 kW. Further, over-sizing is common in the solar industry, as you really only get the full rated power under ideal conditions. Slightly cloudy, early morning etc. and you get less. Also as we discussed, extra panels are fairly cheap.
Lets discuss the current net-metering math. Suppose I use about 10 000 kWh/year, and solar radiance for Toronto is about 1.2 kWh/W year (source). Thus to hit my production target of 10 000 kWh/year, Id need to size a 10 000 kWh/yr / 1.2 kWh/W yr = 8.3 kW. That’s a lot less than the 15 kW potential I could install, hence the opportunity.
So what could policy makers do? Simple, instead of just covering the usage charges of the power bill, why not permit solar to cover other charges as well, say delivery, or customer charge? Looking at my lat power-bill, these two were about 40% of the total bill.
Electric car adventures 