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

[John Colvin]

On Tuesday, 11 June 2013 at 20:02:29 UTC, Walter Bright wrote:
> 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.

A lot of the solar companies give great guarantees on the whole 
setup (assuming they don't go out of business of course). My 
parents have had theirs for ~5 years now with no problems at all, 
other than giving them a quick wipe once every few months and 
adjusting the angle for the seasons.
Admittedly, one has to consider that in the UK they very rarely 
get particularly hot. We also don't get particularly pronounced 
day/night temperature variation compared to some places.

There's probably some good data on the lifetimes somewhere.