1. You'll lose out in the winter.
There is certainly less sunshine in the winter, since the sun spends more time below the horizon and more above the horizon in the summer. Also the sun is higher in the summer, which means a less acute angle to the atmosphere, less air to get through, and stronger rays reaching the earth. Also, depending on where you are it can be more cloudy in the winter and more sunny in the summer. So there's less solar radiation available for electricity in the winter. On top of this, in the winter you tend to use more energy, so there will be less left over.
However, a major factor in generation is the angle of the panels. The steeper the panels are, the more of that winter sun they are going to get. Typical roofs in Japan are too shallow for good winter generation. 35 degrees is optimum for year-round generation. Slightly higher will generate more in the winter, and a little less in the summer.
As we go into the second year, you can see our generation below. The orange line is the manufacturer's simulation, which so far we have out-generated by 5 or 10%:
March was our third best month so far. December was the worst month, but the panels were still generating.
2. You can't store the electricity.
This isn't a misconception. This is usually the truth. But many people have the idea that you can get solar panels, get a battery that will store the electricity they generate, then you can use your own electricity when the sun is down. You could do this, but batteries are expensive, they are not very efficient, and financially you're better off selling electricity you generate to the grid and using electricity from the grid when you need it at night. Looking at our yearly averages, we generate roughly twice as much energy as we use (36 kWh/day compared to 17kWh/day) but we earn about six times more cash than we pay (45,000 yen coming in each month and 7,500 going out, on average). So I'm not rushing off to buy a battery right now.
3. The government is paying artificially high prices for it.
The government is certainly subsidising people who put solar panels on their roofs by offering grants, and is forcing electric companies to subsidise them by paying a high price for solar electricity with a feed in tariff. However, I'm not sure you can call this artificial. This is a government investment in infrastructure that will be contributing to energy generation and making up part of the electrical jigsaw of the future.
Especially when you consider how much is spent on other energy technologies. You don't think private companies set out to develop nuclear power stations on their own, do you? And what about tax money going to building gas, coal and oil power stations? I've been looking around for the answer to my question: how much tax money is spent on energy? It's not immediately obvious, so here are some random factoids instead, from world-nuclear.org.
Based on 2005 data, 40% of the world's R&D spending on energy is made by Japan. Most spending is going on Nuclear fission. Spending on energy conservation, fossil fuel R&D and renewables R&D is similar. A little less is spent on nuclear fusion R&D.
At the moment, solar is an expensive way to generate electricity, but all technologies begin expensive since you're paying for research and development, and manufacturing infrastructure. We've had 150 years digging fossil fuels out of the ground, and have become very efficient at doing that. In fact, a lot of spending on energy efficiency ends up making us better at using energy. The first uses of steam engines were pumping water out of mines, which made it easier to get coal out. So the cost of those fossil fuels is artificially low and nobody is doing anything to replace them. Economically it's the same as clearcutting forest and selling the wood without doing any replanting, only much worst because you'd need a time machine to go back millions of years to replant. Nuclear power has its own issues that I won't go into here.
So subsidies of solar power, rather than artificial, seem sensible and far sighted, especially for a country that produces solar panels and will benefit from demand. It's not such a big deal paying out a few hundred thousand yen here and there to help people put some panels on their roofs, that will generate electricity for the next half century without any need to import leftovers from other country's nuclear bomb factories. Although I don't want to get too political or emotive and I would like to have some more solid statistics to base this on, and know how much the returns on solar power are compared to the investment, and what the real costs of everything are.
4. There are lots of solar cowboys out there.
This is not a misconception at all. The people putting on your panels may be much more interested in getting cash from you, and you getting a grant from the government that will go straight to them. They will be less interested in how much electricity your panels generate over the next half century.
The price of freedom is eternal vigilance, and in the kingdom of the sun blind, the guy with very dark sunglasses is king.
