Slashdot Mirror
France Decrees New Rooftops Must Be Covered In Plants Or Solar Panels
An anonymous reader writes: A law approved in France Thursday now requires all new rooftops in commercial zones to be covered in plants or solar panels. "Green roofs have an isolating effect, helping reduce the amount of energy needed to heat a building in winter and cool it in summer. They also retain rainwater, thus helping reduce problems with runoff, while favoring biodiversity and giving birds a place to nest in the urban jungle, ecologists say." The law was actually watered down from its original version — businesses only have to cover part of their roof.
In other solar power news, reader SpzToid notes that despite earlier worries, the European power grid handled the solar eclipse just fine
Did you miss the words "commercial zone"?
Solar Installer here.
There are two effects at work:
- 15-20% of the solar energy will be converted to electricity and not to heat.
- the air between the solar modules and the roof will transport most of the heat away. This depends on the distance module-roof and airflow.
The effect will be in most cases very noticeable. A first order approximitation is, that normally a roof is 20-30C hotter than the surounding air. With solar modules the roof will be almost the same temperature as the air. On unisolated roofs the effect can be dramatic.
So the plan is to install enough batteries to power the world all night long, and then for a week or two when the weather is bad?
Or is it to put solar all over the Earth and have a massive world wide power grid to move power to where it is needed?
I suppose either is technically possible, I just don't think either is likely to happen.
Read up on baseload power plants: http://en.wikipedia.org/wiki/B...
Essentially solar energy activists aren't out to throw away all coal or fossil fuel plants - just to increase the diversity of power (with a gradual push towards renewables as battery technology and solar extraction improve). Some solar proponents also even support properly implemented nuclear (me!) - anything to get us off the coal crack-pipe.
btw, an industrial scale solar molten salt facility does have a built-in battery - take a look here - its not like this is unfamiliar territory - it's been implemented. http://en.wikipedia.org/wiki/S...
Make sure everyone's vote counts: Verified Voting
Actually there's quite a lot of experience with this type of roof nowadays.
Standard roofs locally are covered with bitumen waterproof covering. THis is affected mostly by UV light, which is countered by layering it over with earth and having vegetation on top of it. This can double the lifespan of the waterproof covering.
The weight of a light covering with Sedum (very small, fatty ground-covering foliage that is very robust) will weigh between 50 and 60 kilograms per square meter. If your roof can't hold that, it will have serious trouble with a big snowlayer. Roofs are mandated to hold at least 100 kg/m^2 over 10m^2, and roofs meant to be used as terrace or walked upon for inspection have to be able to hold 250 kg/m^2.
See also: http://en.wikipedia.org/wiki/G...
Therefore, by the (faulty) logic you're using, you're just a cow with a keyboard - osu-neko (2604)
You need to keep the pots hot all the time, but most of the power consumption goes into electrolytic separation, which you can freely adjust the speed of.