22062010

Quantum dot solar cells - is this the breakthrough?

According to this article and the original paper it looks like we are on the verge of having a solar cell technology that could double the effective efficiency of solar cells whilst keeping the costs the same. So what will this mean in practice?

#1 Double the power in the same space

This is the biggest win - for the same square meter area you get back double the power. Often the limiting factor in solar cell placement is the available mounting space facing in the right direction and at the right angle to the Sun. If the effect energy density is doubled at the same price point - it becomes possible to install solar systems in places previously not viable.

#2 Increased reliability

Having less area doing the same work (or the same area doing more) means there is less physical components involved, so the likelihood of mechanical failure goes down. Also the fact more energy is being captured and converted into electrical energy means less heat energy is absorbed into the panel itself - this will reduce the 'heat stress' the panel experiences during the daily solar cycle - again improving reliability.

#3 A lot more solar, a lot less grants..

The ability to derive power from solar at a suitable rate of return is something which has plagued solar power uptake. In order for consumers to consider going solar, often governments have had to step in with grants or feed-in-tariffs to make the exercise have cost benefits better than just sticking to the old mains supply. Now if solar can indeed get twice the efficiency at the same cost point, this will remove the need for the government to get involved, as simple cost benefit analysis will clearly show going solar is the way to go..

What about existing installations?

People should be able to upgrade to have the new panels, trouble is they should only really do this if they have got to a point where the existing installation has become cost benefit positive in favor of the solar system.



The other option is to just add more of the newer panels to an existing system and uprate inverter and cabling to match. This assumes that you have the space available to do this.

Conclusion

Although we would recommend you don't wait around for this technology to become available when considering solar, we would certainly suggest if a solar installation is looking doubtful to provide meaningful returns for the investment to wait for this. There are also technologies in the works to produce existing efficiency solar cells at cheap cost points, so if you have the space and time, wait for things to improve a little while.