Start-up could solve SA's power problem

Tens of thousands of South Australian homes and businesses have been repeatedly left without power because of storms and the unique ecosystem of the SA power market.

In March, the South Australian Government launched a plan for energy security in an effort to curb these power issues. Key components of the government’s new plan focus on renewable energy storage and gas, and include:

• a call for tenders to develop a 100 MW grid-scale battery storage facility for renewable energy, using approximately $150 million from the Renewable Technology Fund;
• development of a new 250 MW gas-fired power plant to offset the intermittent nature of renewables, expected to cost $360 million;
• legislation to allow the Energy Minister powers for market intervention in the electricity market, for example, to instruct for generators to be turned when required;
• establishment of an energy security target — confirming its commitment to a 50% renewables target;
• $24 million investment in gas exploration under its Plan for Accelerating Exploration;
• gas royalty incentives for landowners.

The pros and cons of Jay Weatherill’s state plan to take control of its energy future have been hotly debated since its release.

According to Dr Kevin Moriarty, chairman of Adelaide-based 1414 Degrees, the government doesn’t even need to look outside its own borders and workforce for the solutions.

Originating from CSIRO research, the 1414 Degrees solution is a patented thermal energy storage system (TESS), which is claimed to reduce energy costs by increasing the efficiency of renewable generation and stabilising grid supply.

A full prototype is now ready for commercialisation after a decade developing this highly complex machine.The prototype development was co-funded by an accelerating commercialisation grant from AusIndustry. Moriarty said that at this stage, approximately $3m has been invested by shareholders.

The solution uses abundantly available elemental silicon for storing and retrieving electrical energy enabling low-cost storage of energy and a stable supply back to the grid — a critical requirement as renewable generation increases, not just in SA but globally. This has advantages from an environmental perspective, as the decommissioning of a TESS is benign. The company said: “Waste produced is solidified silicon that can easily be disposed of or recycled. It does not need to be treated or specially contained and has no damaging chemical impact if it needs to be discarded at the end of its useful life.”

Stabilising the grid

The prototype TESS had its first successful run on 30 September 2016. The company has calculated that it can install sufficient storage, capable of supplying hundreds of MW of electricity, at just $70,000 per MWh to provide for a reliable electricity supply with up to 90% renewable sources and end the blackouts in South Australia. As well as producing electricity, excess heat can also be used to heat water for use in heating and other industrial processes. As a comparison, lithium batteries cost 10 times as much and need to be regularly replaced.

The TESS is differentiated from pumped hydro and solar thermal by having minimal site-specific requirements and is a containerised solution for cost-effective integration in almost any location.

The solution can be placed near grid interconnects, which minimises the additional costs of kilometres of high-voltage lines and their commensurate energy losses and positioning adjacent to a district heating network. This, therefore, reduces the cost of connecting expensive and disruptive infrastructure.

10 and 200 MWh modules are available and can be connected to fill the range from 10 MWh to +2 GWh.

The solution can provide peak shifting by storing renewable generation at times of low demand and releasing at periods of high demand. “A sufficiently large TESS presence on the grid would increase the efficiency of existing wind generation and allow more to be built without risking stability,” Moriarty said.

“Our approach is to build our TESS energy storage units where the clean hot air heat from the turbines can be used for industry and residential heat requirements to displace gas.

“An additional advantage is that the in-built turbines can be fired by gas or biofuel if there is an emergency where renewable sources are cut off, such as happened in the state-wide blackout,” Moriarty said.

According to Moriarty, some of the industries that could benefit from this type of technology and why include:

• Renewable generation could expand, become more efficient and increase cash flows.
• Industries that use large quantities of low-grade heat, such as food processing and production, could access low-cost heat without emissions.
• Cold climate cities and towns use substantial amounts of energy to heat housing and buildings — ‘district heating’. Currently this is sourced from burning gas or from the grid but TESS could store renewable energy at times of low demand (and low prices) and supply both heat and power at a lower cost.

1414 Degrees is now assessing industry and generation sites for its first installations of a 10 and a 200 MWh TESS. Suitable sites for 1414 Degrees would be at a wind farm or near an existing gas-fired generator. The technology will increase efficiency and revenues of a wind farm through load shifting to times of maximum demand.

The company is working towards building the first commercial installations in 2017. It is also now considering a non-compliant tender for the SA Government’s Energy Reform Plan’s emergency gas power plant to incorporate storage with the planned turbine plant.

Case study demonstration example: Roskilde, Denmark

The company has analysed sites ranging from hydroponic farms to regional grids.

A demonstration site near Roskilde in Denmark has been modelled for installation of a TESS to provide district heating and power.

1414 Degrees analysis of the Roskilde site suggests the following suite of generating and storage technologies would provide optimum benefits:

• Wind generation (or access to) (12.5 MWe h/h).
• Solar PV generation (or access to) (4.5 MWe h/h).
• Biomass generation (or access to) (2.0 MWe h/h).
• ERS rating (1.5 MWe h/h).
• Heat store capacity (10 MWhth).

It has been assumed that the demand component of electricity is 50% of the total energy requirement and that district heating and industrial heat requirements comprise the other 50% as is the case for the entire Danish energy demand. Furthermore, the annual energy throughput at a site in Roskilde/Copenhagen has been assumed to comprise 30 GWh of electricity and 30 GWh of heat p.a. for a total throughput of 60 GWh p.a.

The TESS Demonstrator can meet this requirement and, being of modular construction, with a 10 MWh/hth unit fitting into a 40 ft container, is readily located adjacent to the heat load and can be scaled up by adding further TESS modules in series or parallel to meet the Roskilde Kommune site’s power and energy requirements.

The design life of the technologies is assumed to be in the order of 25 years and they provide a technology mix that makes optimal use of energy sources that are readily available, are mostly renewable and enhance Roskilde/Copenhagen’s economic prospects. This includes direct heat for heat loads and avoided cost of waste disposal that can be co-fired with biomass to generate electricity.