DConf 2013 Day 3 Talk 1: Metaprogramming in the Real World by Don Clugston

[Walter Bright]

On 6/11/2013 12:21 PM, John Colvin wrote:
> On Tuesday, 11 June 2013 at 18:47:35 UTC, Walter Bright wrote:
>> On 6/11/2013 8:28 AM, Adam D. Ruppe wrote:
>>> It is great stuff, solar power is almost free money if you can wait 20 years for
>>> it.
>>
>> Yeah, but you'll have to replace it before 20 years!
>
> Source? There's not much that wears out in a photovoltaic AFAIK. The associated
> electrical components may break however, especially on some of the more complex
> setups.

Don't have a source, I read it long ago. Note that none of the advertisements, 
brochures, etc., mention expected life of the PVs.

I do know that the life of any semiconductor is measured as the integral of the 
heat it experiences. Heat causes the doping to migrate, and when it migrates far 
enough the part fails.

PV panels can get pretty hot in direct sunlight.

Heating/cooling cycling will also cause cracking.

If you're considering a PV system, I'd ask serious questions about the useful 
life of the system, and what maintenance is required (at a minimum, they'll need 
the dirt and mold regularly cleaned off).

Circuit boards, inverters, etc., also fail, and you'd need some assurance you 
can get replacement parts for 20 years.