The Adelaide solar industry has been experiencing a degree of uncertainty over the last 12 months as the Renewable Energy Target review threatened to reduce or even eliminate the small scale renewable energy scheme (SRES), which effectively ‘subsidises’ the upfront cost of solar system installation. The Federal Government now has created more certainty for the solar industry by maintaining the existing scheme for small scale rooftop solar installation. Year on year the number of solar installations in South Australia continues to grow and South Australia remains the state with the greatest percentage of residences with solar systems installed.
Solar Storage – The Next Quantum Leap In The S.A. Solar Industry?
As we reported in a previous post, the emergence of high energy density battery technology and decreasing prices is bringing the possibility of residential solar energy storage to South Australian’s at a rapid rate. As the South Australian feed in scheme essentially only provides for a “minimum retailer payment” of 5.3 c/kWh it makes little sense to ‘sell back’ solar power generated from a solar system for a rate significantly less than the current rate of grid supplied electricity. Being able to ‘store’ excess solar electricity in a battery system means that power is available for use within the home at night time – when many households’ energy usage is at its peak. The design of combined solar systems and energy storage systems needs to be tailored to ensure the solar system generates the sum of the daytime household energy consumption plus the evening / night time consumption, whilst the energy storage system needs to be sized to store the evening / night time energy capacity.
Tesla PowerWall Solar Energy Storage
There has been widespread media coverage over the last few months regarding the release by U.S. Tesla Motors PowerWall which is a Lithium Ion battery unit designed to meet the emerging demand for compact solar energy storage aimed at the residential market. The ‘PowerWall’ unit features include:
- 7Kwh daily cycle energy capacity per unit with ‘stackability’ capability, meaning that several units can be installed should a greater storage capacity / energy usage be required by the household.
- Lithium Ion Battery Technology used. Lithium ion technology has the benefits of extremely high ‘energy density’ – meaning a lot of energy can be stored in a relatively physically small battery unit and offers low maintenance. Couple this with a 10 year life span and this adds up to an ideal technology to store solar energy.
- Wide Temperature Operating Range. Given that Adelaide and South Australia can experience scorching summer temperatures and cold winter temperatures it is critical that any solar battery storage system be able to operate within that temperature range. Battery technologies generally suffer from a decreased operating lifetime as ambient temperature increases. The Tesla units are designed for efficient cooling to address this issue.
- 92 Percent Efficiency. In any electrical system energy ‘losses’ are a reality. A well designed solar system and energy storage system aims to minimise these losses, meaning the maximum amount of stored solar electricity is available for use within the home. The Tesla unit is rated at 92 percent efficiency.
It will be very interesting to see if this potentially ‘game changing’ technology will gain acceptance in the Adelaide solar market. It is interesting to note that some of the major ‘energy retailers’ are currently “touting for interest” in energy storage systems, meaning that they see this as an inevitable ‘step’ in the energy industry and need to be involved with it. Interesting times in the solar industry in Adelaide lie ahead it seems.