GM to build world's biggest rooftop solar station in Spain

[seven]

US automaker General Motors said Tuesday it will equip the roof of its factory in Zaragoza in northeastern Spain with solar panels to create the world's largest rooftop source of power from the sun.

GM to build world's biggest rooftop solar station in Spain

[hoon]

Good to see GM taking these things more seriously these days.

[prashamk]

Great, one who has huge share in current global emissions is now into reducing it in a big way.

[debs]

Nice one GM. Now they need to do the same at their US plants.

[macgardener]

Good news. Should be more of it. All those huge roofs just sitting there doing nothing. Come to think of it, rather than doing nothing, wouldn't a large steel roof over a commercial building be increasing the temperature inside the building, requiring more power to run the airconditioning to cool it down. Much better to intercept the heat before it reaches the building and put it to use in a good way. Or is that not the way to look at it?

[LMagic007]

Yes Mac that's a good point you raised about the panels helping block out some of the heat from the sun, so the overall efficiency of the panels might in a way be said to be even higher in net energy consumption / production terms. i.e helping producing energy ( kWh ) and also helping save energy ( kWh) by shielding the roof and thus reducing the heat transmission into the building in summer. One thing however is that during winter this may be an undesirable effect, where you want to maximize the solar radiation into the building.

Thus ideally if you could channel the heat that hits the solar panels into a large thermal storage tank, which could be used in winter for helping heat the building. i.e via some piping under the panels to conduct the heat away and into the tank. This could be a bonus in summer and not only do you get heat removed into storage for later energy use, you get the building shielding as mentioned before thus reducing air conditioning load in summer and also you get better performing solar cells that typically perform better when they are cooler. In fact because the way buildings are insulated, it may well be more energy efficient to capture the heat in winter for storage and later re-use, rather than allowing it to simply hit a bare roof without solar panels on it. Thus with the hybrid solar PV / thermal solution you might get a triple energy utilization benefit with such a configuration.

In fact, I'm now convinced we need a hybrid PV / thermal solar panel, that have a symbiotic relationship as described. The panel is the host that thrives on solar radiation to produce electricity, whilst the heat sink is the parasite that kindly removes the heat from the PV panel to help improve its efficiency, whilst also storing the heat for later energy production or direct re-use for space heating.