Declining electric demand undercuts power line proposal
The disruption of the electrical power industry began with the introduction of Energy Star appliances and improvement in building practices in both residential and commercial markets. Energy efficiency slowed the growth in the demand for power. The downturn in the economy and generally slower economic growth added to the reduction.
The federal government then introduced solar energy credits for homeowners at the 30% level. That provided substantial incentives for homeowners to take a look at rooftop solar. State rebates and incentives were added to the mix. In Pennsylvania Governor Rendell introduced the Pennsylvania Sunshine Solar Program, with rebates at an initial rate of $2.25 per watt as the incentive.
Pennsylvania quickly shot up to be the third fastest growing state in adding rooftop solar in both 2011 and 2012 behind California and Arizona. Rooftop solar puts distributed generation where the demand is and offsets any requirement for added grid electricity.
The growth has slowed in Pennsylvania, but the additions of rooftop solar in Maryland and Pennsylvania are still steady. SEIA (Solar Energy Industries Association) projects there are currently over 52,000 rooftop solar arrays in Maryland and almost 20,000 in Pennsylvania (2017 data). Maryland has 779.9 MW of installed rooftop solar, Pennsylvania has 347.63 MW of installed solar. Both states have solar jobs (an estimated 8871 jobs) and solar installers active in supporting and growing this industry. In addition SEIA projects an addition of 1065 MW of additional rooftop solar in Maryland and Pennsylvania combined over the next five years.
Since a rooftop solar array is 98% efficient with the array approximately 50 feet from the homeowner’s electrical panel, this 1065 MW is equivalent to approximately 3195 MW of grid power, which is only 35% efficient. Why such a huge difference? Grid power must travel 50 to 100 miles or more to reach the homeowner’s electrical panel, overcoming line losses, transformer losses, and substation losses along the way. The further that grid power travels the less efficient it becomes.
A solar panel’s capacity has improved steadily since 2010. The increase has been 35%, increasing from 230 watts per panel in 2010 to over 300 watts per panel in 2017. The increase will continue. That means the homeowner can get a 35% increase in wattage for the same roof area on their home or garage.
Costs have come down from $7.15 per watt in 2010 to about $4.00 per watt in 2017. Panel size is expected to increase and costs are expected to decrease in the coming year. On a net cost basis it is actually cheaper to add a rooftop solar array today than it was back in 2010.
There is one final technology that will add to the decline in grid power. That is battery technology. Backup batteries have largely not been used with solar arrays except in buildings a mile or more off the grid. With a home or building close to the grid the owner uses the grid as their backup power. The cost to run a power line to a home even one mile off the grid is prohibitive. When necessary, because of a remote location, homeowners have used a combination of power management and backup batteries to run their homes.