As the problem of exported solar gets mainstream attention, solutions will become ever more inventive.

Surplus solar is a good problem to have, but it’s still a problem. Solar energy that is exported to the grid because there is no use for it – or no battery – in the business or household that owns the PV system can cause issues in some networks. As more rooftop solar is connected, the problem grows.

The Australian Energy Market Commission is recommending rule changes that could see PV owners charged for exports, which would incentivise self-consumption or investment in storage. More broadly, some networks are installing community batteries to absorb solar exports and the Federal Labor Government has even committed to spend $200 million to install 400 community batteries across the country should it win the next election.

As the problem of exported solar finally trickles into mainstream consciousness, interesting solutions are being pitched to consumers.

In Sydney, window furnishings company Hunter Douglas has worked out a way to sell the electricity generated by its 800kW rooftop system that is generated outside weekday work hours.

Hunter Douglas has partnered with energy retailer Simply Energy in its Solar Sharing Plan, which is enabled by Powertracer software developed by Enosi. The smarts in the platform allow for solar exports to be allocated to employees whose energy needs typically spike on the weekends when they are at home. This energy also comes at a discount to grid-supplied energy.

Powertracer works by matching generation with consumption, using data from smart meters at the producer’s and user’s ends. The technology works at any scale, from utility to residential, says Enosi CEO Steve Hoy. “The Hunter Douglas solar system exports quite a bit, on weekends and holidays and so forth,” he says. “They’re a customer of Simply Energy and so are the staff joining up to the plan, so a trade is created on Powertracer where we match excess energy with staff consumption.”

For every kilowatt-hour that is matched, Simply Energy’s billing system credits the customer 5 cents. Simply pitched the idea to Hunter Douglas when it was asked to submit a tender for its energy supply. Although Simply’s bid was not the lowest, Hunter Douglas saw value in the extra dynamic of selling discounted surplus solar to its staff and signed up with the retailer.

If Hunter Douglas can do it, then so can owners of many other commercial and industrial solar systems. “The key to this is to engage the staff, to bring them into it,” Hoy says. “That will be the key to the success of these plans.” Depending on the enthusiasm and number of connected staff, the ability to sell exported solar may also be an excuse to oversize an existing rooftop system. Consumers only need a smart meter, which in this case is being supplied free by Simply. They needn’t have solar at home.

To your door

A different kind of incentive is being offered by Carlton & United Breweries, where beer drinkers who sign up to electricity retailer Diamond Energy have the option of exchanging every $30 of exported solar energy for a case of Victoria Bitter, delivered to their home (so long as a few terms and conditions are honoured).

“There are only 500 spots available,” says Victoria Bitter general manager marketing Brian Phan. “While we want to have more people exchanging solar credit for beer down the track, for now any beer lover who wants to participate should sign-up quickly at www.vbsolarexchange.com.au.”

Anyone who misses out can obviously take the amount credited by their existing retailer for exported solar and spend it on any beer they like. Or food.

Carlton’s beer-for-solar program is enabled by peer-to-peer trading software developed by Perth-based company Power Ledger.

In 2018 the brewer signed a 12-year power purchase agreement for 74,000MWh a year of renewable energy from the 112MW Karadoc Solar Farm near Mildura, Victoria.