Solar: Does Size Matter?

A key issue for scaling up solar is where to put it: on every home or in huge arrays on the desert?

Some businesses, like Sungevity, are trying to get solar panels on every home by breaking down the up-front cost barrier. They partner with financial institutions to spread the cost of going solar into a zero-money down monthly lease. This would allow more homeowners to invest in solar panels for their own homes. In urban settings, this can be particularly useful because cities can start to take advantage of previously unused productive space and generate energy for the city.

On the other end of the scale, the folks at Solar Reserve are thinking 2.5-square miles bigger is the best way to store solar energy for large-scale distribution.  They use thousands of mirrors to reflect and concentrate sunlight onto a central point to generate heat, which in turn is used to generate electricity. They can take advantage of places like Tonopah, Nevada, where it’s sunny 50% of the time, to build the largest solar tower project in the world.

Or, maybe it’s smarter to take a more regional approach. The George Washington University has teamed up with Skyline Innovations and installed three solar thermal systems on the roofs of GW’s residence halls. This energy system collects energy that students can use in their  dorms for hot water.

What do you think? Personal, utility-scale or regional: does size matter?

Bonus: Do you know how solar panels work? Brush up on your solar knowledge with this Science Corner on how solar energy works:

1. 
   On February 25th, 2012 at 12:29 pm Brett Kuntze Said:

   I often wonder if rooftop solar panels blocks the sunlight from radiating through the roof to warm up the attic during the wintertime.. It may be beneficial during summertime as the shadow of the rooftop solar panels doubles up as a shade . The gain from the solar panels may be cancelled out by the lower temperature indoors as a result fo the shade being cast by the solar panels during wintertime. Maybe it evens up, I dont know really. Also, I think that it is more difficult to install several kilowatts on a roof than to sell them in smaller kits like 500 watt array with a far more powerful attic fan than those available in stores.. Those available in the stores has only 15 watt solar panel which is not enough to cool down the attic during the daylight hours. Moreover, we can keep the attic fan going during nighttime because air is cooler and can be drawn into the attic to cool down the insulation batter while we sleep. This will buy a few extra hours of cool indoors before air conditoning kicks in. Air conditoining consumes several kilowatts a hour and if you delay the need of air conditioning by a few hours on a hot day because of the cool down of the attic with a solar attic fan, you save probably 10 kilowatthours daily or more. Nighttime air is a natural air conditoiner so why not suck some in to cool down the attic. You cannot do much if it is static during the night. I use a regular fan to cool down the attic during the nighttime and I can see the big difference!

2. 
   On April 5th, 2012 at 8:33 pm Serge Young Said:

   There is always the economy of scale so the bigger the production facility the more efficient it would be. That said I still think it makes sense to put solar panels where ever we can. There is no reason every house in America that has good solar exposure shouldn’t have solar panels on it. We have a ton of space on highway medians that is easily accessible and could serve as great place to create solar electric generating plants.

3. 
   On May 6th, 2012 at 2:08 pm Gumby Said:

   I believe that solar photovoltaics can be placed practically anywhere from big farms to rooftops. As for inverters (used to sell electricity back to utilities ), rooftops has cost disadvantages despite recent advances on inverters. Rooftop solar photovotlaics can be used directly (off grid) without having to use costly inverters and related installation costs. We can use rooftop photovoltaics to power more powerful attid fans to really get the attic temperature way down than now.. We only make solar attic fans that come with weak solar panel only up to 40 watts or so.. You cannot really cool down hot attics with only 40 watts… You need 300 watts or more.. You can also power a supplemental room air conditoner with your rooftop photovoltaic. A good sized room air conditoner requires about 1000 to 1500 watts that can be added to relieve your central air conditioning system that typically require way more than 6000 watts or so. Rooftop solar photovoltacis is great for direct uses ( off grid). Your utiltiy prefer to buy electricity from your rooftop photovolatic than letting you use it yourself .. You dont really need inverters for selling back to your utilty .. This is the reason rooftop installations is uneconomical.. Utitliies is probably trying to throw monkey wrenches into our efforts to have rooftop photovolatics by insisting that you install inverters you dont really need most of the time.. Shareholders want to earn dividends from utilties so it is their ill gotten self interests not yours ..

4. 
   On May 6th, 2012 at 2:11 pm Gumby Said:

   Utilites know that off grid solar photovoltaic applications can really chop down their reveneues so they insist to buy electricity away from your abiility to use it for yourselves to save even more.. When you talk about energy conservation, your utility is not your best friend.. They are interested in more revenues , energy conservation be damned and it can wear lipstick for all they care..