A gravity-fed energy storage system under development by Gravitricity may be more cost effective in the long term than batteries, according to a report by Imperial College London (ICL).

The Gravitricity technology could be particularly well suited to provide grid balancing and rapid frequency response services to grid operators, the report said.

The technology has high operational expenditure, but this is offset by a long project lifespan of up to 50 years, high power availability and zero percent degradation, ICL said.

Gravitricity technology will use a weight of up to 2000 tonnes suspended in mine shafts by cables attached to winches.

The weight is winched to the top of the shaft to capture renewable power and then dropped to release it when needed, with the winches acting as generators.

Gravitricity managing director Charlie Blair (pictured) said: “This independent report clearly shows that Gravitricity can be a very strong competitor in the frequency response market, where its low specific power cost and high cyclability sets it apart from other technologies.”

On a plain 4,700 metres above sea level in Tibet, a solar farm harvests the sun’s rays. It is absorbing this abundant source of power to help generate the clean energy required to satisfy China’s burgeoning demand for electricity. This sun-drenched farm is part of a growing phenomenon where a 150-year-old technology, the lead battery, is becoming one of the most reliable solutions to the problem of storing and supplying the energy of the future.

While lead batteries are more commonly associated with the technology under the bonnet of your car, starting the engine, powering the safety features and electronics, it is also one of the cleanest and most reliable options available in the green energy revolution.

In Tibet, with up to 14 hours of sunlight a day in the peak months between April and July, the plant run by China Shoto, part of the Shuandeng Group, uses lead batteries housed in containers on site producing 30MW of solar power supported by 20MWh of energy storage.

By choosing advanced lead battery technology, the company argues it is able to offer reliable, safe and long-lasting storage for up to 10 years, switching supply on or off according to the requirements of the grid.

The system is being replicated globally with projects in the United States, Africa, the Middle East, Europe and across southeast Asia, which are quietly changing the face of energy storage.

Lithium and lead – two leaders in rechargeable battery storage

REV launched in 2014, and spans at least 16 major proceedings, along with the investor-owned utilities’ rate cases.

On energy storage, the PSC said it “opened the door to distributed generation suppliers seeking to connect energy storage technologies to the distribution system, allowing for projects up to 5 MW to come on-line.”

Regulators also said they “enhanced” the Standardized Interconnection Requirements application and contract process, in order to make the interconnection process more efficient. Those rules determine how distributed generation developers connect projects to the distribution system, to avoid delay.

In upstate New York, New York State Electric and Gas got approval for new rate structures in its Energy Smart Community project, and can now implement time-differentiated options. Regulators said the pilot rates aim to “convey strong price signals” that focus on the system peak. “For each service classification, the off-peak rates are at least 2.5 times less than the on-peak rates, which send a clear price signal to customers, and provides them with a greater financial incentive to manage their energy usage,” the PSC said.

Regulators also directed creation of the Utility Energy Registry, an online platform that will offer public access to customer-load data for the major utilities. With the registry, the PSC also adopted a privacy standard for the provision of whole building data for apartment buildings.

The registry aims to “help create a more information-centered power system,” the commission said, supporting the exchange of information among utilities, customers, service providers and other third parties. The project will begin in the middle of this year.

The price of household battery storage is defying hopes and expectations of significant price falls, with two of the leading manufacturers – Tesla and Enphase  – quietly lifting their prices in recent months.

The household battery storage market in Australia has been poised for take-off for a couple of years, but most consumers have been keeping their powder dry on the expectation that prices would continue the dramatic falls of the last few years.

Tesla set the scene with the release of their Powerwall 2 product in late 2016 which effectively halved the cost of battery storage, at least compared to the Powerwall 1, and forced most competitors to match those prices.

But nothing much has happened since. In fact, prices have now started to edge up.

Tesla quietly lifted the price of its Powerwall 2  by $US400 to $US5,900 in February this year, and the Australia price followed suit – to $A8,600. These prices do not include installation and other costs.  Prices for Enphase batteries have also risen slightly.

The rises are being blamed variously on supply bottlenecks and the jump in price of certain commodities, particularly cobalt.

A Tesla spokesman in the US told Greentech Media said the company “evaluates its global pricing of energy products based on various factors and continues to make improvements that will simplify homeowner experience.”

Enphase told RenewEconomy it blamed supply “bottlenecks” for its minor price increases, but said it hopes to be able to reverse these price rises later this year.

Lockheed Martin has received an order to supply about 17MWh of GridStar Lithium energy storage systems to Peak Power, an energy storage services provider.

The units will be installed in Ontario, Canada, and along the East Coast of the United States.

Lockheed Martin Energy vice president Frank Armijo said: “Peak Power Inc. is an innovative company that we are excited to collaborate with to deploy our robust, reliable GridStar Lithium systems.

“These projects are an example of solutions we’re providing to address complex global energy challenges.”

Peak Power Inc. will use its own intelligent Synergy software, combined with GridStar Lithium energy storage systems, to forecast the most expensive peak demand events and shift energy consumption for its customers during these peak moments.

This results in a reduced amount of peak demand on the grid and lower electricity costs for customers.

Peak Power CEO Derek Lim Soo said: “The Lockheed Martin name is a brand that is associated with a proven track record and high-quality design and engineering.

“Our software performance this past year in Ontario allowed us to hit all five coincident peak events that form the bulk of our customer’s bills within a one-hour window, with 100% accuracy.

“We’re looking forward to integrating our software with Lockheed Martin’s reliable and innovative solutions to support our customer’s needs and the future of our distributed grid.”

Lockheed Martin has delivered and has a pipeline of energy storage solutions to address a range of applications, including reducing peak loads on the electrical grid and integrating renewable energy sources with energy storage.

These projects have been installed in many locations, including Canada.

Lockheed Martin Canada CEO Charles Bouchard said: “Our mission is to deliver solutions to our customers’ most complex problems through applying innovative approaches, and through establishing strong, strategic partnerships.

“Lockheed Martin Energy has an excellent track record of providing comprehensive solutions across the energy industry, and our work with Peak Power Inc. is a great match to address complex energy needs across both Canada and the United States.”

The Vermont-based nonprofit said its report, Jump-Start: How Activists and Foundations Can Champion Battery Storage to Recharge the Clean Energy Transition, should prompt action and support to advance battery storage, either deployed alone or paired with renewables.

The publication surveys 10 areas where batteries are transforming the energy system, from reducing demand charges to replacing peaker plants.

It also proposes 50 actions nongovernmental organizations (NGOs) can promote to accelerate rates of battery storage adoption, including investigating new behind-the-meter market opportunities, creating energy resilience plans and funding criticalsolar-plus-storage projects.

“This report is for activists and foundations who want to understand how battery storage can become a new part of their clean energy and climate advocacy,” states the publication. It notes the document is designed to explain the emerging economic, equity and environmental trends for battery storage use across all elements of the energy system.

The publication comes as NGOs increasingly move to embrace battery storage as a key ingredient for future low-carbon scenarios.

In the U.K., for example, the advocacy group Greenpeace lists “giant batteries” as one of four measures, including flexible gas plants, that can help wind power’s capacity to support the grid.

Friends of the Earth, another global environmental group, also cites batteries as part of the equation for an energy system based largely on renewables. Electric cars and batteries will “stockpile electricity for us,” says the group.

Beyond the rhetoric, a robust defense of battery storage has already helped advocacy groups win some battles against the fossil-fuel industry.

As reported in GTM, for example, NRG’s efforts to build the Puente gas plant in Oxnard, California were set back last year after a coalition of clean energy concerns, environmental justice advocates and the city itself touted energy storage as a cleaner alternative.

The California Independent System Operator studied the local grid needs and determined storage and other distributed assets could do the job of the gas plant.

Storing energy by suspending weights in disused mine shafts could be cheaper than batteries for balancing the grid, new research has found.

According to a report by analysts at Imperial College London and seen by BusinessGreen, gravity-fed energy storage systems can provide frequency response at a cost cheaper than most other storage solutions.

Gravity-fed systems use a heavy weight – up to 2,000 tonnes – suspended in a deep shaft by cables attached to winches. When there is excess electricity, for example on a windy day, the weight is winched to the top of the shaft ready to generate power.

This weight can then be released when required – in less than a second – and the winches become generators, producing either a large burst of electricity quickly, or releasing it more slowly depending on what is needed.

The Imperial analysis is based on a levelised cost of storage (LCOS), a calculation which takes into account all relevant performance factors including a project’s capex, operating costs, discount rate and degradation costs over a 25-year period.

According to the paper, gravity-fed storage providing frequency response costs $141 per kW, compared to $154 for a lithium-ion battery, $187 for lead acid batteries and $312 for flywheel.

The numbers assume the storage performs 700 cycles per year of 15 minutes each, at a power output of 4MW, to help manage the real time grid balance between system demand and total generation.