They’ve been used as a rubber additive, a carbon-capture medium and a bioplastic ingredient. Now, discarded eggshells may have yet another use. Scientists have determined that they could be utilized in an eco-friendly and inexpensive form of energy storage.

An international team of researchers started with regular chicken eggshells, which they washed, dried and crushed into a fine powder. That powder consisted both of the calcium carbonate outer shell, along with the protein-rich fiber membrane found inside.

The material was then used as an electrode against a metallic lithium anode, within a non-aqueous electrolyte. When tested, the resulting battery cell was found to maintain a capacity retention of 92 percent, over the course of more than 1,000 charge/discharge cycles (capacity retention is defined as “a measure of the ability of a battery to retain stored energy during an extended open-circuit rest period”).

This energy-storage capability came thanks mainly to the calcium carbonate, which allowed the crushed egg shells to store lithium. It is now hoped that the material could be incorporated into a low-cost lithium-ion capacitor.

As the mix of energy sources feeding power-hungry homes, businesses and industry comes to incorporate more renewables like wind and solar, society faces a reckoning with where to turn when wind and sunshine die down. What will it take for greener sources not only to join fossil fuels on the American power grid, but eventually to displace them?

In February 2019, Los Angeles announced plans to phase out three natural gas power plants by 2029 and to replace them with a combination of renewable energy and battery storage. A few months earlier, the California utility Pacific Gas & Electric won regulatory approval for similar plans. It hoped to replace a trio of natural gas plants with industrial scale battery storage systems, including a 730 megawatt-hour project to be designed and built by electric car company Tesla Motors. For comparison, the two small plants slated for retirement in PG&E’s plan can generate up to 47.6 megawatts of electricity when needed, while a larger natural gas plant in the project can produce up to 606 megawatts.

The idea behind both plans is that the capricious nature of energy from sunshine and wind creates a problem for operators who need to match the amount of energy supply at all times to the amount of demand. Storage technologies including batteries offer a way to maintain the supply-demand balance by drawing electricity from the grid when renewables are abundant and sending it back when demand picks up or renewables’ output falls short.

Both the Los Angeles and PG&E plans have some unusual factors. But even so, they may offer glimpses of a future in which large-scale battery storage helps ease the way for the kind of energy mix that growing numbers of states demand. California mandated last year that all of its electricity come from zero-emission sources by 2045. And clean electricity legislation is on the table this year in states including Minnesota, New Mexico, New York, and Washington state. In California, regulators are also requiring PG&E and the two other investor-owned utilities to procure at least 1.3 gigawatts of energy storage capacity for the state’s grid by 2020.

NYSERDA’s filing is “an enormously positive step” in the state’s deployment goals, Bill Acker, executive director of New York Battery and Energy Storage Technology Consortium (NY-BEST), told Utility Dive. It will advance New York’s goal to reduce greenhouse gas emissions 40% by 2030 and shift to 100% carbon-free electricity by 2040, he said.

The plans follow Gov. Cuomo’s announcement earlier this month of new emissions regulations aimed at phasing out less efficient power plants and encouraging plant owners to replace the lost capacity with battery storage or other clean energy options. Along with the storage target, the state also wants to add 9,000 MW of offshore wind by 2035 and 6,000 MW of distributed solar by 2025.

Under NYSERDA’s plan, “incentives are offered at a fixed amount per AC kWh of usable storage capacity.”

Retail incentives can be applied to standalone or paired storage projects of 5 MW or less, considered on a first-come, first-serve basis, starting at $350/kWh and winding down as each funding block is filled.

Bulk incentive programs are offered in all state investor-owned utility service areas besides that of Consolidated Edison, which is running its own bulk incentive program. Projects under 20 MW will receive a projected $110/kWh, ramping down $10 each year until 2025, subject to market changes. Projects over 20 MW that will begin operation within the next two years will receive either $85/kWh or $75/kWh, depending on the class year.

According to Acker, the bulk market storage incentives were not included in the original January plan and were added in response to stakeholder input.

An energy storage system has been installed at the largest single-site solar park in the world.

The battery storage facility has been built at the Mohammed Bin Rashid Al Maktoum Solar Park in Dubai and marks the first storage system to be twinned with a PV plant at a grid-scale level in the United Arab Emirates (UAE).

NGK Insulators supplied the batteries and electrical engineering company Ingeteam was responsible for the supply of a 1.2 MW power conversion system with its medium voltage components, plus the power plant controller.

UAE utility Dubai Electricity & Water Authority (DEWA) want to evaluate the effectiveness of the storage system in stabilising grid fluctuations caused by the intermittency of renewables.

The storage system will be also used for energy time shifting, frequency control and voltage control by using the large capacity of the batteries.

The solar park is being built in phases, has a planned capacity of 1000 MW by 2020 and 5000 MW by 2030 and will use both photovoltaic and concentrated solar technologies.

The 13 MW first phase became operational in 2013 using PV panels, with a 200 MW second phase launched in March 2017. A further 800 MW of PV will be online by 2020.

The fourth phase of the solar park will be a concentrated solar park and will feature the tallest solar tower in the world at 260 metres.

This story originally appeared on our sister website, Electric Light & Power.

Insurer Munich Re has launched what it claims is the world’s first long-term insurance plan for battery performance, signing up ‘all-iron’ flow battery maker ESS Inc as its first customer.

One of the insurer’s management board, Peter Röder, described the ability to insure battery performance as a missing “key piece of the puzzle in decarbonising our energy sector”.

“For the first time, battery manufacturers can insure against the risk of their products not delivering as promised,” Röder said.

Aimed at major projects such as stationary storage systems deployed for grid stability or peak demand reduction applications, manufacturers will be able to give customers performance guarantees by backing their warranties for 10 years.

Munich Re claimed manufacturers can “unburden their balance sheets” because insurance will cover the cost of repair or replacement of defective battery modules that exceeds the agreed cover amount. The insurer said this should also make it easier to obtain project financing for stationary storage projects, by capping the maximum costs of warranties. Cover can be extended to individual projects, meaning customers are covered even in the event of manufacturer insolvencies.

Energy-Storage.news reached out for expert opinion and commentary on the launch and Munich Re’s claims – from both an independent advisory firm and an energy storage market research company – but did not receive replies in time for the publication of this story.