Saturday, July 31, 2010

The case for a standard solar day

Here is an idea that the Department of Energy (or NREL) should develop to assist mainstream consumers adopt solar. In keeping with the Energy Star program this could be called the "Solar Star" rating. Please note: I have no idea if this is being (or has already been) tried, it just seems like it would be helpful.

The US solar industry would benefit from establishing a standard solar day (or location). This would facilitate manufactures and installers to compare products under equivalent conditions while allowing consumers to easily translate the performance of these products to their local conditions.

Let's say that a standard solar day is defined as 4.8 hours peak insolation per day averaged across the year (a more detailed/realistic standard can be constructed by adding other relevant parameters like temperature, and/or breaking the day into sub-periods). Some software programs used to estimate solar system production already incorporate rich/detailed models--but I'm willing to bet that each s/w program does this differently--a standard day could make their jobs easier too.

A person in a region that only gets 4.5 hours of peak sun on average, multiplies the standard performance of a system by 0.94 to find out how the product would perform in their location. Someone that gets 5.3 hours on average would multiply the standard performance by 1.1 to learn how the product performs in their location. Etc.

I believe this will help the industry, especially as solar becomes an economically viable option in more than a handful of states across the country. Manufacturers should be happy to demonstrate/advertise how their product performs against a single standard. They already do this to a certain extent, unfortunately the standards they use (STC or NOC) is not terribly helpful or informative for customers. Installers with a national presence should be equally happy to provide an installed cost for a "standard watt" with modifiers based on size and type of installation. Local installers could use a standard watt price to quickly/easily expand regionally. In many cases a customer could use their zip code to determine/calculate their locality modifier (if the installers don't already build that into their quotation software).

Friday, July 09, 2010

Solar power for Afghanistan?

I recently read about the trouble the US military is having delivering power/electricity to Afghanistan. This is similar to difficulty the military had (continues to have?) in Iraq.

It made me think that we should--at least as an experiment--give the Afghanis solar panels, and let them install the panels. Some people may think this is crazy, but let me explain.

We are spending over a hundred billion dollars each year on our military to "win hearts and minds" over there, with very mixed results. Solar panels would provide a positive legacy for decades to come. Just a few million dollars invested in solar would make a huge "splash".

1) solar can scale to fit the need--from a few watts to a few megawatts

I think this is critical, especially as I am calling for an "experiment"; we can experiment big, or small or anywhere in between.

2) solar panels are cheap, $2/watt is roughly half what they cost 2 years ago

3) solar panels can be installed quickly (installing a couple panels is simple...especially with microinverters)

Points 2 and 3 are relative to other distributed power sources at equivalent scale. FYI in the US the "installed" cost of solar is high for reasons that have little to do with the cost of solar panels. And depending on the "size" of the experiment, we would get feedback within weeks or months.

4) Afghanis use a lot less power than Americans, so each kW of solar goes much further

5) distributed generation works well in difficult terrain

Points 4 and 5 are the kicker, especially for the military. The military can distribute the panels however they want. Afghanis don't need a 5kW array to power their home, they would get a major benefit from even a couple 200 Watt panels. And finally a couple solar panels on a thousand homes would not provide a single target to attack the way a central power generating station does.

Does this "idea" solve every Afghan problem? Heck no--it is not intended to. It is intended to solve one very specific problem of providing electric power (relatively quickly) in a very scalable and distributed way in very difficult terrain.