Bi-Facial Solar Modules

Value for Ground-Mounted Solar?One of the biggest news from the last 2016 Solar Power International trade-show in Las Vegas was claimed bi-facial modules yield gains.According to manufactures the gains consist of: – higher efficiency cells capturing direct light; – bi-facial gain from the light reflected from the ground; – reflections from surroundings and from the diffused light; – virtually no light induced degradation.Based on new LG NeON 2Bi-facial specs, on a ground covered by snow the bi-facial gains for example are expected to be 26.8%. These gains may be negatively affected by choice of racking that will partially reduce the amount of light coming from the back.On a positive side, one can expect the gains to be even higher due to: – snow melting on bi-facial modules faster; – early morning and late in the evening bi-facial system will reach min operating inverter voltage sooner.Finally, higher energy density results in lower balance of system costs. A smaller amount of piling, racking, inverters, combiners and wiring needed to be installed to reach the same generation yields. Bi-facial PV system would also take less space on the ground. Taking all these effects into account could triple the economic benefit of bi-facial modules.The current challenge to qualify the added value of bi-facial ground-mount installations in Canada is in the lack of real time performance data. Until these data become publicly available, the true added value of bi-facial modules will remain a bit mysterious.