Solar cost calculators have proliferated on the web in recent years, and here are my reviews of some of the top results in a Google search for them.
This is a decent model with time-to-payback and easily adjustable assumptions.
This is not as good a model as the last one, and apparently designed mostly for choosing system size.
This is a good model but more complicated and industry-specialized. It has lots more detailed information attached, though.
This is a good, simple residential system-size calculator.
This calculator appears pretty comprehensive but is not easy to read.
I’m suspicious of some of the results of this calculator, as they differed significantly from the others. The calculator seems quite comprehensive but is complicated and not easy to read, and maybe I wasn’t using it correctly.
This calculator is pretty simple and easy to use. Answers may vary from those given by other models.
The first calculator I listed may be the best, but try several and you can find the one that answers your specific questions best.
Overview of Rooftop Solar in the United States
It appears that rooftop solar power cost has now fallen below a break-even of 18 years or so, depending on the details, which finally makes a 25+ year system lifespan attractive. The costs are will continue to drop, though, and solar (and wind, and other renewable energy sources) will only become more attractive and economical.
Converting voluntarily to renewable energy sources will keep fossil fuel costs low as demand will be limited, and while that actually decreases justification for renewable energy, it is a boon to consumers who rely on fossil or mixed fossil and renewable energy sources. People around the world today seem more and more conscious of the need to stop using fossil fuels and to reduce carbon dioxide and other types of air pollution, and this is driving a strong upward movement in the market for renewables. It is clear that producing solar panels generates far less carbon emissions than they will save, contrary to some rumors, and it is heartening to see people embracing renewable energy sources more and more.
While the widespread adoption of renewable energy sources will mitigate the ecological and economic problems caused by overpopulation, it will not eliminate them. Renewable energy buys time for us to figure out how to live in ways more friendly to the planet, but the population and birthrate must inevitably decline (or be voluntarily reduced by humans). Otherwise, if the global population continues to increase, the production of solar panels and other renewable energy equipment may enable the population to reach even higher levels before some key resource starts to be exhausted and the planet reveals how many people it can actually support. Note that the number may be billions lower than the number the planet supports now, though.
Please talk about the overpopulation problem with anyone who will listen. It has critical ramifications as a causal factor for practically every single problem humanity faces. We each need to contact our political representatives, ask them for their views on overpopulation, and make it clear that reducing birthrate and figuring out how humanity can survive the next century is far-and-away the most important topic for discussion today. Our grandchildren will live or die young depending on what we do today.
Thanks for reading — Tim.