The Energy Storage Report 2024

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Top picks of the year from PV Tech Storage

Tom Werner explained that while companies like SunPower and their rivals want to offer their customers more choice, there is little interest in doing so at the expense of utilities. Image: SunPower.
Covering the energy storage market has been an interesting – if occasionally bumpy – ride so far and we can expect it to be an even more vibrant and action-packed space from here on in. We’ve seen energy storage of many sizes, scales and usages discussed this year, from Germany starting to find its feet as the home of residential solar-plus-storage, to California utilities starting to make real inroads in meeting the state’s 1.35GW storage mandate. Here are the top five most-read news stories from the year:

1: Sunpower CEO: Grid independence is naive

No surprises that for a site which has been born from our existing offerings in the solar industry, the top story this year focused on words from one of the PV industry’s big names. Tom Werner, head of SunPower, one of the US’ biggest solar companies, followed SolarCity’s Peter Rive in saying that, while utility companies should certainly understand the disruptive threat posed by solar-plus-storage to their existing business models, bypassing the grid entirely and going it alone without the utilities is not a realistic option, even for the bigger of the mainstream solar providers.

“…grid independence is naïve,” Werner said.

“SunPower has never taken the position that the utilities will be obsolete.”

It’s interesting to see after years of tension between solar and utilities, especially in the US. While storage could in theory offer people the chance to divorce entirely from the grid, batteries could also be one thing that diffuse this tension and keeps them there.

Leading SunPower for more than 10 years, Werner has seen his company go from manufacturing solar modules to providing almost every solar energy-related service you could think of. Along with rivals SolarCity, this has led SunPower to the logical position of being among the first big movers in energy storage from the big US solar installers. It will nonetheless require creative thinking on the utilities’ part, something Werner and Solarcity spokesman Will Craven both told us this year, but the good news for utilities is that the rumours of their death spiral appear to have been exaggerated.

2. Solar cell-battery hybrid developed by Ohio State University team

Is this solar-plus-storage taken to a literal, logical and somewhat fantastical conclusion? A team from Ohio State University came up with a device which literally combines a solar cell with a “breathable battery”. In simple terms, the cell, besides sounding and looking like the fevered dreams of a science fiction writer, could be truly special not just for combining the functions of solar cell and battery, but because combining these functions means that the battery component can store almost 100% of the electrons generated by the solar. Typically, around 20% of the electrons are lost in the movement between solar cell and battery. The team, led by supervisor Yiying Wu, say they expect their cell to be licensed for industrial use, but the journey from lab to widespread deployment is always a difficult one.

3.IHS: Residential PV storage market to leap tenfold by 2018

It’s not often a research report will tell you that something has failed to live up to the hype after years of being talked about as the “next big thing”, but also that that same thing is likely to now rocket to ten times its current size within the next four years. That’s exactly what market research experts IHS said in a November report, when they predicted that residential energy storage will rocket from 90MW globally this year to 900MW in 2018.

Admittedly the base it is starting from is a fairly low-key one. For example, Germany, one of the world’s leaders, only installed about 4,000 residential PV-plus-storage units in the first year of a support scheme for buyers of lithium-ion based systems. However, as Sam Wilkinson, research manager at IHS pointed out, residential PV in Germany will be more attractive with storage than without by 2016, in his estimation. IHS is certainly not alone in predicting a great leap forward - GTM Research has highlighted the US solar-plus-storage as being close to a "tipping point" in its path to becoming a billion-dollar industry.

“The three key variables that determine whether it’s economical to add energy storage to a residential PV system to increase self-consumption are the value of the feed-in tariff, the expense of buying electricity from the grid, and the cost of energy storage products. And all of these metrics are moving in the right direction,” Wilkinson of IHS said.

4. Canada’s first grid storage system launches in Ontario

With a decent amount of hydroelectric generation and ambitious renewable energy targets, Ontario launched a Long Term Energy Plan in 2013 which mandated the installation of 50MW of storage. This spawned the first grid-connected storage system in the region – a 2MW flywheel hosting rotors, each several thousand kilograms in weight. This project for balancing the output of renewable energy generation goes to show the variety of technologies that energy storage can encompass.

As PV Tech scribe Ben Willis wrote in his article about the project, “…the facility uses a spinning steel flywheel on magnetic bearings to store energy in the form of kinetic motion, rather than chemicals, as are used in battery systems”. The so-called Minto flywheel system will allow Ontario’s Independent Electricity System Operator (IESO) to balance the grid in real time, by matching scheduled generation with actual consumption. Following the installation of the flywheel, in July 33.5MW of other energy storage projects were selected for Ontario, from a range of technologies.

5. US utility Con Edison chooses storage over billion-dollar substation project

One story that turned heads this year and came in at number five on our list was the news that one US utility could use energy storage to save itself from having to spend as much as US$1 billion on upgrading a transmission substation. Serving the New York area, utility Con Edison has asked for permission to explore using demand management to prevent the need for the costly work. As Dean Frankel of Lux Research later explained in a guest blog for the site, the utility could save as much as US$800 million.

“The demand reduction programme is projected to cost US$200 million, and will include 52MW of demand reduction technologies across utility-owned distribution assets and customer-side resources.”

From a total of that 52MW, Frankel wrote, “Con Edison is seeking to implement 41MW of customer-side demand reduction by 2018 for a total cost of $150 million, and 11MW of utility-owned demand reduction for US$50 million.”

This combination of customer-side reduction with front-of–the-meter measures is intriguing. The specific mix of technologies is yet to be decided but it is particularly interesting to see both types of storage talked about in New York, which has seen far more energy storage action in scales way above the residential so far, for the most part. Although we’re assuming most people were drawn to the story by the astronomical sums of money involved, if we’re being totally honest.

Dr Tim Fox of the UK's Institute of Mechanical Engineering wrote about using renewables and storage to empower farmers in developing countries. Image: wikimedia User: saravask.
We’ve also been lucky to receive guest blog posts from some distinguished experts and industry players. Here’s a quick run-through of three of my favourites among those blogs:

Cold Chains: Connecting farmers in developing economies to market options through energy storage - Dr Tim Fox, Institute of Mechanical Engineering (IMechE)

Dr Tim Fox, Head of Energy and Environment at the Institute of Mechanical Engineering (IMechE) in the UK brought us an unusual angle for storage but a worthy one and one that would ultimately represent a huge amount of installed capacity if realised. Dr Fox talks about how farmers in the developing world, often in regions with abundant renewable energy resources, could empower themselves through “establishing a continuous chain of temperature controlled cold environments from the point of harvest to the marketplace and on into the home".

Hawaii’s big storage experiment - Dean Frankel, Lux Research

Analyst Dean Frankel of Lux Research contributed an interesting case study on Hawaii. Unsurprisingly, as an island territory with high levels of PV penetration, Hawaii needs to protect its grid system while relentlessly continuing to add to its renewable energy generation sources. Frankel blogged in depth on the details of Hawaiian Electric Company’s request for proposal (RFP) to deploy between 60MW and 200MW of energy storage and went a step further in his explanation of how the programme could serve as a “case study for the rest of the world”.

The advantages of scalable electricity storage technologies - Melissa C Lott, University College London

Engineer Melissa C Lott, originally from the US but now an energy systems engineer and doctoral researcher at University College London, was the primary author of a roadmap for energy storage technologies produced by the International Energy Agency earlier this year. She wrote for PV Tech Storage about how the scalability of electricity storage systems is likely, along with market design, to define the technologies and their usage for years to come.

Wolfram Walter of ASD Sonnenspeicher charges his "homemade" Porsche EV. Image: ASD Sonnenspeicher.
…and finally, here are a couple of my favourite interviews of the year:

NY BEST: The Big Apple’s storage landscape

John Cerveny, director of resource management at New York Battery and Energy Storage Consortium (NY BEST), which he describes as a combination of trade association and economic development agency, talked us through the big picture on storage in the Big Apple. NY BEST has grown in tandem with the state’s energy storage industry, talking frequently with policy makers while also directly assisting industry participants with technical matters including research and development. As such, Cerveny and his organisation are well placed to illuminate the wider global industry on the issues facing one of the world’s leading regions for storage. For example, in October, when New York State Energy Research and Development Authority (NYSERDA) awarded funding to several companies developing prototype storage systems, Cerveny was uniquely well-placed to offer insights and comments into the story for us.

Best laid plans: The boss of an accidental storage company

At the other end of the spectrum from New York’s mostly grid-connected, large-scale storage landscape was the story of Wolfram Walter of German firm ASD Sonnenspeicher. Having given us an entertaining, irreverent and informative video interview at the Intersolar show in Munich this year, we were intrigued by Walter’s story of how he developed a residential storage system for his house which snowballed into a commercial enterprise, producing storage units for residential and commercial customers. Walter’s trail of discovery didn’t stop there either – he claims to have turned his Porsche sportscar into an EV and connected it into the circuit of a rudimentary smart home. With Germany broadly ahead of the curve in the modestly growing world market for residential PV-plus-storage systems, Wolfram Walter’s story gave us an unusually detailed glimpse into the work and motivations of one of its hopeful participants.

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