8.3 Growth in energy generation from solar

The National Electricity Rules (NER) define an intermittent generator as one ”whose output is not readily predictable, including, without limitation, solar generators, wave turbine generators, wind turbine generators and hydro-generators without any material storage capability”. This definition of an intermittent generator fits well with most industry experts’ understanding of solar intermittency, some to a higher extent than others. Some believe a good forecasting system, once developed, will be able to predict solar intermittency to a certain degree, as wind output is now predictable for the purposes of NEM (National Electricity Market) dispatch.

Solar industry stakeholders were asked what proportion of Australia’s generation they believe is likely to come from all forms of solar, including small- and large-scale photovoltaics (PV) and concentrating solar thermal (CST), in the next five, ten and fifteen years. The responses (averaged and rounded) are shown in Table 17, along with a comparison with corresponding estimates from the Energy Sector Model (ESM), a long-term investment planning tool for the Australian energy sector developed by CSIRO [65], for two carbon reduction strategies (CRPS-5 and G-25). The main reason for delayed uptake of solar in the ESM is mainly due to the cost competitiveness of wind.

Table 17 Estimates of Australian solar penetration (PV and CST) by 2016, 2021 and 2026

Time Responses of Australian solar industry stakeholders CPRS-5 strategy based prediction G-25 strategy based prediction
5 years (by 2016) 4% 0.2% 0.4%
10 years (by 2021) 8% 3.2% 3%
15 years (by 2026) 18% 8% 8%

Some factors that might constrain the growth of energy generation from solar in Australia are:

  • cost-competitiveness of solar technologies vs. other types of generation
  • government policies/intervention
  • grid integration is a likely issue - this depends on AEMO and TNSPs managing large-scale intermittency with significantly higher penetration levels of intermittent generation and distribution networks managing voltage fluctuations arising from distributed solar (mainly PV) export
  • lack of reliable and economic energy storage to reduce intermittency impacts
  • lack of transmission networks in large-scale solar areas
  • design of existing distribution systems.

The limiting factors above can be overcome by:

  • making solar technologies more cost-competitive in the energy market
  • managing solar intermittency issues (some lessons can be learned from wind integration)
  • greater investment in transmission network in remote areas with high solar resource
  • a more favourable regulatory environment
  • developing smart inverters
  • strategic planning
  • developing accurate prediction methods of solar power.