Battery storage gains traction
A growing number of market operators are beginning to recognise the commercial value of energy storage as the technology finds applications in traditional and new energy power plants
In comparison with the multifaceted complexities of energy markets, the commercialisation of energy storage has seen a smooth and bright ride over the past few years. Energy storage has risen from obscurity to garner unanimous support.
Commercialisation of energy storage is now expected to not only stir up the renewable energy push in the region, but also foster changes in energy sectors like the oil and gas industries. It will not only change the shape of the existing market, but also break ground for new markets with the capacity for nearly unlimited growth.
“Energy storage is the new trend. It will not only make an energy revolution a real possibility, it will deeply transform humanity’s production methods and lifestyles,” says Andrea Mansoldo, principal consultant, Power Systems Planning, DNV GL – Energy.
A growing number of market operators are beginning to recognise the commercial value of energy storage, and a growing number of energy storage technologies are finding applications in traditional and new energy power plants.
The recent announcement that the world’s largest lithium-ion battery will be installed in South Australia is lending rare optimism to proponents of utility-scale battery storage around the world.
This feat is expected to transform and fast track reliable renewable energy not only in Australia, but also around the world where this form of energy, while highly desired, remains short of guaranteeing dispatchable electric supply whenever needed.
While the GCC region is rapidly stepping up its adoption of renewable energy largely through utility scale pv solar plants, the main challenge has been how to sustain power production when the sun goes down. This is where proponents of utility scale battery storage are convinced that the technology could help address the problem.
However some utilities in the region remain sceptical about utility scale battery storage for pv solar plants arguing that the technology is still expensive and that would be long before it reaches grid parity.
“Storage, especially battery storage technology is not proven yet. We need time to test its effectiveness both in cost and as an application. However, we continue to channel resources into our R&D about the technology,” says Saeed Mohammed Al Tayer, CEO and MD of Dubai Electricity and Water Authority (DEWA).
Thermal storage through Concentrated Solar Power (CSP) technology seems to be the most favoured form of utility scale storage at the moment with a number of regional utilities planning to ramp up their CSP capacity.
Dubai is planning to commission its first CSP project in the fourth quarter of 2020 with a total capacity of 700MW, enabling it to generate solar power even after sunset. The emirate will eventually generate 1000MW of CSP from the Mohammed Bin Rashid Al Maktoum solar park.
Unlike photovoltaics, which generate a charge directly from the sun’s power, thermal plants use mirrors to concentrate heat on water, turning it to steam to drive a turbine. The heat can be stored in molten salt to be used later.
“I expect concentrated-solar power, within 18 months, to be head to head with combined-cycle gas, if not more competitive,” Says Paddy Padmanatha, CEO ACWA Power International.
“The focus has been on PV and batteries, but there’s a limit on how long they can hold a charge for. We’re proving that CSP can work through the night.”
Since it can retain heat, the plant can keep working after dark. The sun’s energy in some cases can heat molten salt to 490 degrees Celsius (914 degrees Fahrenheit), which allows operators to predict when electricity will flow.
But overall, energy storage technologies have gained attention and approval as the key to balancing traditional power generators, enabling grid integration of renewables, and supporting distributed energy resources, electric vehicles and the development of the energy internet.
Rapid developments in electric vehicles have arisen due to accelerated growth among mainstream lithium-ion battery manufacturers. The industry has become increasingly rational and differentiated.
Following the blossoming of a wide variety of energy storage technologies, lithium-ion and lead-carbon batteries have the potential to become the backbone of the energy storage industry in the next few years.
Meanwhile, flow batteries, compressed-air energy storage (CAES), and hydrogen storage are now beginning to expand in scale. Early movers are the first to know the trends. In 2016, a growing amount of capital was injected into the energy storage market, and EV battery manufacturing leaders garnered favour from capital markets.
The most mature energy storage technology is pumped hydropower, generally utilised for longer periods of charge and discharge. Pumped hydropower represents the vast majority (99%) of storage in use and is economically and technically proven throughout the world.
The potential for a new 400MW/2,500MWh pumped hydro energy storage site is already being investigated in Dubai. This follows the award of a consultancy contract by DEWA to an arm of EDF for a 250MW pumped hydro project under development at Hatta Dam in the UAE’s Hajar Mountains of the United Arab Emirates, a contract that was awarded by DEWA.
One reservoir of water will be built high up in a mountain for the Hatta Dam Water will be pumped from the Arabian Gulf using solar-powered turbines. When energy demand increases, and production costs are high, turbines operated by the speed of waterfall from the upper reservoir will be used to generate electricity, with an immediate response to energy demand.
Examples of other emerging storage technologies are adiabatically compressed air energy storage, flywheels, power to gas and supercapacitors. Electricity can also be stored in thermal form using boilers, heat pumps, ice or chilled water, for instance.
Thermal storage can be integrated with combined heat and power production and utilised to maximise wind resource penetration.
Thermal energy storage options are often cheaper than other forms of storage, though it is more difficult to reverse heat storage back into electricity. Typically, electric energy converted to a thermal medium is used at another time as thermal energy, either for space heating, cooling or in industrial processes.
The fall in battery costs has been happening at the same time as the steep fall in the costs of renewable energy sources. Another concurrent trend relevant to both technologies has been the rapid advances made in technologies for the inverters, isolation transformers, and collection systems needed to tie in multiple direct-current systems into grids that operate on alternating current.
“It is not surprising that we are seeing these technologies coming together in systems that allow utilities to manage the inherent variability of wind and solar power generators that can only supply electricity when the wind is blowing or the sun shining,” says Andreas Becker, head of grid and power storage, AEG Power Solutions.
“Surplus power generated during these periods can be used to charge utility batteries, which can then supply electricity when power from the variable sources is insufficient.”
While increased uptake is noticeable mostly in the area of battery energy storage systems, several barriers have to be overcome before battery storage technology is fully integrated as a mainstream option in the power sector. These include performance and safety issues, regulatory barriers, and utility acceptance.