Significantly, the per-watt price for utility-scale solar continued to decline in 2014 to $1.80 â 59 percent below where modeling in 2010 predicted it would be this year.arger utility-scale systems are projected to reach $1.30 to $1.95 per watt in that year. The cost per watt of a solar photovoltaic cell has fallen off a cliff in the last few decades, plunging 99 percent since 1977.