The use of photovoltaic (PV) systems, otherwise known as solar panels, is growing rapidly with 93,914 systems connected to the Western Power electricity grid.  As of September 2011 Mandurah had installed the most systems (3507) followed by Canningvale (2397) and Padbury (2351).

Whilst reducing the size of the power bill is usually the major motivator for installing PV’s, they will also significantly reduce your emissions; a 1.5kW system will save approximately 2.7 tonnes of CO2 emissions, per annum (compared to coal powered electricity).

For many that is incentive enough but in theory PV’s may actually impact on costs in more ways than simply reducing household consumption of energy from the grid.

One of the key issues for electricity providers is that approximately twenty percent of the infrastructure is built to cope with the top two percent of the load (the amount of power consumed).  In Perth, peak demand normally occurs on very hot days when air conditioners are blasting out cool air.

This equates to millions of dollars in infrastructure being put in each year to prevent brown outs (not enough energy to cope with demand) or black outs (no available energy) on a few days a year. If we can manage the peak we may reduce the infrastructure required, which is currently around $9,000 per lot, reducing the capital cost of delivering energy in new developments.

For many households, peak use is in the evening when the family arrives home from work and afterschool activities to cook dinner, watch television and use other power hungry appliances. Preliminary results obtained within the Perth Solar Cities trial showed households that do not have PV systems have their peak consumption (1.5kw) at 6:15pm whilst those with a PV system have their peak consumption from the grid at 7:15 pm (1.48kw).  This is logical given the PV systems operate until the sun goes down, effectively delaying their peak use from the grid.

PV’s, when combined with energy efficient appliances, will help reduce both overall consumption and the peak.  By 2017 Western Power is anticipating that PV capacity will increase 73 percent to 472mw reducing the peak by 2.95 percent. This may potentially impact on the level of infrastructure required.  In the longer term it is hoped that there will be agreement that the current high level of infrastructure in new developments is no longer necessary, which will have a positive impact on housing affordability.