It is one of the most common complaints about solar. What if a person cannot afford to install their own solar array. What if their home or building is not suitable for solar panels. How do you get solar to all the tenants of an office block or residents high rise residential building.
It is a question that is often asked in Australia, which has the highest rate of penetration in the domestic market in the world.
In states such as Queensland and South Australia, one quarter of all customers have rooftop solar on their homes, and many are looking at solar for “self consumption” or even as a means to quit the grid. Many others, though, are missing out. Renters can’t get access, inner city and apartment dwellers have nowhere to put them.
The answer, according to the US-based National Renewable Energy Laboratory, is “shared solar”. In a major new report released this week, NREL says that one half of all distributed solar installations in the US could be in the form of “shared solar”. And shared solar could be the key to expanding the potential customer base of solar to 100 per cent of homes and businesses.
The concept of community ownership is not new. It has driven the huge investment in renewable energy in Denmark and Germany, in particular. In Australia, there are scattered examples such as the Hepburn Wind Farm, the Albany wind farm, and community owned solar projects such as this one in the Shoalhaven and the planned installation on the new Sydney exhibition centre.
But there is growing interest. Councils are becoming increasingly focused. In Byron Bay, they are testing the idea of “virtual net metering”, where the output of solar electricity from one building is credited to the consumption of another. In other words, the output is shared. A community-owned energy retailer is also being put together.
Other councils, such as Lismore and a group of six in western NSW, are looking at different financing models to build solar installations where the output can be sold to the community. Councils such as Sunshine Coast and Fremantle are looking at large scale projects – in the region of 10MW to 15MW – to do the same.
A number of councils and towns in NSW and Victoria are looking at 100 per cent renewables, which will inevitably include “shared solar”. The Melbourne City Council has tendered for solar suppliers for interested business buyers in the CBD.
It’s a critical issue in Australia, because the move to “self consumption” risks causing major impacts on embedded infrastructure such as networks. There is no doubt that the networks have been over-priced – because of the massive investment in the last 5-10 years – but the grid remains the cheapest “back-up”.
That, in turn, however, means that the grid has to learn how to “share” energy generated on individual properties. Right now, tariff designs and policies make that difficult, pushing more and more consumers and businesses to consider quitting the grid altogether. Up to one third of customers may choose to do that, the CSIRO has said, unless networks, retailers, policy makers and pricing regulators learn how to adapt to the new energy paradigm.
The NREL report underlines the point that shared solar models allow consumers to jointly own or lease systems to offset electricity bills, and allow consumers to share the benefits of a single solar array.
NREL estimates that at least 49 per cent of US households and 48 per cent of businesses are currently unable to host a PV system when excluding residential renters, those without access to roof space and/or those living or working in buildings with insufficient roof space.
If the policy factors can be addressed, shared solar could lead to another 11GW of distributed solar over the next 5 years, an investment of more than $16 billion.
“Options such as shared solar can enable rapid, widespread deployment by increasing access to renewables on readily available land and rooftop sites, lowering costs via economies of scale, and fostering innovation,” the report says.
“Fundamentally, these models remove the need for spatial one-to-one mapping between distributed solar arrays and the energy consumers who receive their electricity benefits. The output of offsite solar arrays can be shared among residential and commercial energy consumers lacking sufficient unshaded roof space to site an array.
“Solar developers can construct arrays in optimal locations on marginal lands or unused rooftops and offer community members the opportunity to participate directly and benefit.
“Shared solar arrays sited on apartment buildings and shopping malls can provide stable electricity bills to landlords and tenants. Retailers and municipal buildings that host shared solar systems can provide electricity and other benefits to the community and generate goodwill.
“Utility-sponsored shared solar programs can reach large numbers of energy consumers.”
There are other benefits too. In the event a shared solar customer moves, his or her solar share can be transferred separately from his or her residence to a new home within the same utility service territory or sold to another entity.
“Shared solar arrays allow for increased siting flexibility: strategic placement on sites such as commercial rooftops, brownfields, and municipal land can aid local economic development,” the report says.
“With utility input, strategic deployment can also aid grid integration. For utilities, shared solar arrays can function as a more streamlined and visible electricity-generating source than many smaller systems.”