What output (per square metre) is likely?
If we assume a cell power conversion efficiency of 3% the output would be at most 30W for a solar input of 1000 W per square metre ( we receive at best only about ~850 W per square meter in Scotland); an efficiency of 5% would give 50 W and 10% would give 100 W. Our goal is to extend the efficiency from a base of 5% up to 10% and beyond, which will be achieved through continuous investment and enhancement in our development process, resulting in step measured improvements.
What is the potential cost per kWh over the course of a year, if in constant use?
If we take existing thin-film cell modules then the module cost with which we have to compete is ~£1 per Watt peak, Wp, (calculated on the maximum output that the module can produce), so that a module producing 50 Wp would cost ~£50 (~twice the cost of Si crystalline cell modules); in UK people hope to obtain ~100 kWh per square metre per year.
What sort of durability is likely? What is the expected useful lifetime of products(s) in various conditions (e.g. constant vs occasional use)?
Lifetime testing will need to be undertaken to meet the specific environment of a particular end use. We have yet to do any lifetime tests - it is likely that longer lifetimes will require more elaborate and costly encapsulation, so accordingly there will be a range of products depending on the expected lifetime and site conditions.
What are the temperature ranges in which the product is viable?
All solar cells de-rate with increase in temperature – especially the output voltage which drops about 2 mV per degree C rise - we expect our cells to behave in the same fashion.
Can the product be cut to shape on site and maintain efficiency without the need for rewiring by a skilled technician?
To some extent we could produce cell arrays on a roll that could be cut between the cell “strings” but certainly not across any active cell areas. The electrical contact pattern between cells will define the combination of voltage and current delivered by an array and this will largely be determined at the production stage, but different arrays could be fabricated on the same roll of material.