The best solar panels are those that produce the most power and last the longest. The most common ranking system for solar cells is called Silver, which pits a cell against all others in terms of efficiency, voltage, current and reliability. Based on this Sunshine List, Aussie modules (nicknamed 'Solarbac' after Australian company Solarbac) have a Lead Efficiency of 15.5%, but as usage levels go up these low efficiency products tend to lose their top ranking spot since they decrease faster than those with higher efficiencies.