Thursday, April 16, 2015

Bankability of Large Solar Arrays

Greetings from the Australian National University where Rhett Evans from UNSW is speaking on
"Understanding the technical justification of bankability requirements in large PV installations". He commented that photovoltaic (PV) panels are an immature product at the stage of TVs in the 1960s (bought from a specialist TV store). Also he claimed that almost all of the cost-effectiveness of PV has come from improvements in manufacturing, not from the efficiency of the cells. In his research he concentrates on the technical assessments which underpin large scale solar investment (and what can go wrong). Rhett pointed out that research shows that the major failure cost with PV is not the cells or panels, but the electronics in the inverter.

It occurs to me that PV panels, on their own, may not be a "product" at all. The emphasis has been on making solar cells which can produce electricity at a price to compete with coal fired power stations. However, consumers don't buy power from power stations, they buy it from a distributer after it has been delivered over a distribution network. Much of the cost to the consumer is not the cost of generating the power, but in allowing for peak use, distribution and the cost of selling at the retail level. The cost of electricity to the consumer is made up of (approximately) 45% wholesale, 45% network and 10% retail cost. So for power which the consumer produces for their own use on site will not be subject to the network or retail costs. Also consumers don't want power, they want hot water, cooling, cooking, lighting and gadgets. It might therefore make sense, for example, to provide heating and cooling closely coupled to the PV panels. This may not be worth retrofitting to existing individual bespoke detached houses, bit worthwhile for factory made modular homes and apartment blocks.

One of the implications for Rhett's work on Failure mode, effects, and criticality analysis (FMECA) is that perhaps inverters should be kept separate from PV panels, so they can be easily fixed.

No comments: