It’s bad enough travelling around suburban areas and seeing so many houses with naked rooftops just begging to have solar panels installed on them; that feeling of lost opportunity is magnified a hundred fold when driving through an industrial area or past a large shopping centre. With rooftops by the hectare soaking up the sun, why are we putting them to work?

Generation where it’s needed

Industrial areas and shopping centres are major users of electricity. Using local roofs for solar power locates electricity production within short reach of major electricity consumers. Power networks allow for losses of around 15% in transmission over long distances. In an industrial estate the short distances between producers and consumers mean little in the way of such losses. On top of this, the electricity infrastructure is already there – no new transmission lines are needed.

Cheaper power

A major reason why the businesses that occupy large industrial buildings would want to go solar – if they can use most of the electricity they produce it works out cheaper than buying power from the grid. Large shopping centres are ideal candidates, as demonstrated in the US by Walmart, IKEA and Target. By late 2016, 238 US Target stores will have 122 MW of installed capacity, equivalent to a sizable broad acre solar farm. Even plastered with solar panels, retail buildings consume all of the power generated on their expansive roofs, so they can’t be held to ransom by the puny feed-in tariffs offered by many utilities.

Other good candidates for a solar makeover (or build-over) are open-air car parks.

Ownership vs benefit

Most commercial properties are leased by the businesses that occupy them, and in the past this has presented a problem: it’s difficult to align the interests of the building owner and the tenant. Finance models like that being pursued by the Sustainable Melbourne Fund could go a long way to overcoming this.

Another alternative is for building owners to simply rent out their rooftops to power companies that then negotiate power purchase agreements with building occupants, or cooperate with community funding schemes, possibly incorporating community net metering.

Land use and aesthetics

Whether it’s an endangered desert tortoise in California or taking up arable land, large solar farms on the ground can have environmental consequences. While it may cost more to install large solar arrays on commercial buildings than on the ground, land use issues are avoided. Depending on the ownership structure the land component of industrial rooftop power may be nil.

There are no (or few) aesthetic problems. Joe Hockey might find wind turbines “utterly offensive”, and it’s understandable that many people might object to panelling over productive farmland, but installing panels on industrial roofs really shouldn’t upset too many people.

Getting smart about it

A few people might need to rethink things to bring about this vision of turning industrial and retail areas in solar power stations. Some current regulatory structures and commercial attitudes will need to change and greater cooperation from power utilities will be needed (something they are not renowned for). Also on the wish list is new ways of allowing community participants in solar projects to benefit from their share of production.

There are potential problems with exploiting some industrial roofs; things like structural and wind loadings and penetration of the roof with mounting screws. But in many cases these are not insurmountable, and perhaps, thinking longer term, the construction codes for large buildings could include a requirement that they be compatible with solar panels.

Scalability is one of solar power’s great strengths. Australian households have proven how viable it is at the smallest scale with millions of systems in operation. Isn’t it time we put thousands of Australia’s larger rooftops to work?

Image: iStockphoto