How Much Land to Power The Whole World with Solar?

[Haanu]

Solar power systems installed in the areas defined by the dark disks could provide a little more than the world's current total primary energy demand (assuming a conversion efficiency of 8%). That is, all energy currently consumed, including heat, electricity, fossil fuels, etc., would be produced in the form of electricity by solar cells. The colors in the map show the local solar irradiance averaged over three years from 1991 to 1993 (24 hours a day) taking into account the cloud coverage available from weather satellites.

http://www.ez2c.de/ml/solar_land_area/

Hey, it's not like we were using Nevada for anything, anyway!

[include]

If they made it a standard to install solar panel roof tiles on all new houses built in europe, north america etc. the overall effect of solar would be dramatic.

Originally Posted by include

If they made it a standard to install solar panel roof tiles on all new houses built in europe, north america etc. the overall effect of solar would be dramatic.

It'd be incredibly expensive. Many home owners probably couldn't afford it. It'd also require more production capacity and silicon than we currently have, by several orders of magnitude.

[include]

Originally Posted by wolranes

It'd be incredibly expensive. Many home owners probably couldn't afford it. It'd also require more production capacity and silicon than we currently have, by several orders of magnitude.

Well, the higher the demand, the lower the price gets. 20 years ago, look how much silicon chips cost. Now you can get a gigabyte worth of flash memory for next to nothing.

Imagine how the world could change if the proportional cost of solar panels dropped just like pc chips have. I know it's not exactly a great comparison, but the general rule still applies.

[porges37mer]

I agree, and Greenpeace and several other organizations did reports saying that there would have to be a production facility ~500MWs in order to lower the costs of PVs to where people would actually want to buy them.

[Richard]

Originally Posted by include

Imagine how the world could change if the proportional cost of solar panels dropped just like pc chips have. I know it's not exactly a great comparison, but the general rule still applies.

They may well happen, but not overnight. Computers took decades to get to the stage where they were small enough, fast enough and cheap enough for the public to be interested in them. I expect solar power will be the same. It will have its day, but not just yet.

[include]

Sure would be cool if it did!

[BillJ]

Originally Posted by include

If they made it a standard to install solar panel roof tiles on all new houses built in europe, north america etc. the overall effect of solar would be dramatic.

1) Photovoltaics are still inefficient, the power from them is very expensive, they don't last forever, and there's an environmental cost to manufacture / dispose of them. They also lose efficiency even more when they get hot, so they work best in cold areas with lots of strong sunlight, like high altitudes. They have their place, but not on a big scale. Not yet anyway.

2) Solar heating can be very efficient in the right climate. There's a huge area of the North American interior with cold winters and year-round sun. Putting solar-assisted heat in a new house would probably pay now, in some climates, but even if the ammortization looks long now, you can only expect energy costs to rise.

I don't understand why all the new houses in those areas aren't being built with roofs laid out in such a way that solar panels can be added later. You spend $400,000 for a new house built with no thought to possible solar adaptation ; what will it be worth in 20 or 30 years? Or as soon as people realize that it might be a good idea.

[LMagic007]

Originally Posted by include

If they made it a standard to install solar panel roof tiles on all new houses built in europe, north america etc. the overall effect of solar would be dramatic.

HYPOTHETICAL EXAMPLE ONLY

Well they just have to lower interest rates to help compensate for the higher cost of renewable solar power on houses roofs. If the average mortgage is $300,000 then lowering rates by 1% will save $3,000 per year so in 3 years without effecting demand in the new housing market they could simply lower interest rates by 1% for new housing and make it mandatory that every new house has solar panels. ( Either grid connect of battery backup systems. Add in Micro wind as an option.

For lack of a better measure, a 1kw generation capacity = 1% interest rate discount or whatever suitable. You can mix and match to suit, though best to keep it as simple as possible.

In 3 years you have recovered your money for a $9000 system via the discounted 1% interest rate. Plus add on to that the electricity savings over 3 years. If your average power bill is $1500 per year and you system saves 75% of power then you save an additional $1125 per year or $3375 over 3 years.

In year 4 onwards you continue to save because interest rates are kept low by keeping the incentive discount interest rate policy in place. Thus so you save $12,375 per year with combined energy and interest rate savings.

Demand for new housing is balanced as before and existing housing can apply for the rate discount if they install solar. A deal can be done between the Government, Reserve Banks and private banks.

If you paid cash for your home then you can probably afford solar.

This may sound economically controversial, but I think it makes good sense to me. You replace lower new housing demand caused by higher new house prices with mandatory solar systems, with lower rates to on average equal the net cash flow effect based on the average loan size.

You see interest rates mostly benefit the wealthy, because when rates are low the wealthy can borrow more to invest and lock in low rates and when rates are high the wealthy can get the best returns. The more money you have, the greater your discount when investing. You get treated better by the banks. Wealth is relative of course but I'm speaking the real wealthy, but that's another topic.