Rainmaker
We develop, own and operate utility-scale battery storage and grid-flexibility assets across European markets — the physical layer that lets a power system built on weather stay dependable.
For a century, the question in electricity was how to make more of it. That question is largely answered. Europe added renewable capacity faster than almost anyone forecast, and the cost of a megawatt-hour from sun or wind is no longer the problem.
The binding constraint is now time. Sun and wind produce when they produce; demand arrives when it arrives. Germany's wholesale price fell below zero in 573 of the 8,760 hours of 2025 — hours when the system paid to be relieved of power it could not use. Within the same week, the same grid was short and expensive. The average day-ahead spread across a German day that year was about €130 per megawatt-hour. That distance is not a market failure. It is a missing asset class.
Storage closes it. Not as a technology story, and not as a bet on any single revenue line, but as the ordinary, unglamorous, load-bearing infrastructure that a weather-powered system needs in order to behave like a grid.
Electricity is the one input that every other system assumes. It is invisible until it is absent, and when it is absent nothing else in the list below continues to function. We work at that layer — not because it is exciting, but because it is load-bearing.
Electrification of heat, process and transport is moving industry onto the grid. Supply-chain resilience is now, in part, an electricity question.
Data centres and AI compute are among the fastest-growing loads in Europe, and among the least tolerant of interruption. Compute is electricity, held in a different form.
Price volatility in power passes through to everything downstream. A system that can move energy across hours is a system with fewer extreme prices in it.
Europe has spent this decade learning what dependence on imported energy costs. Storage does not produce a single electron, but it decides how much of what Europe already makes actually gets used.
A battery on a grid is not a product. It is a position in time.
Most platforms in this sector are strong in one of these and buy the other two. We think the value lives in the seams between them, which is why we hold all three.
We acquire and progress projects where the unglamorous work is already done or can be finished: a signed grid connection, a granted permit, a secured lease. Connection queues across Europe hold far more capacity than will ever be built. Which projects are real is a question of paperwork, not press releases.
A storage asset earns over fifteen years or it does not earn. That makes cell chemistry, thermal design, warranty structure and the credit quality standing behind a performance guarantee financial questions, not engineering footnotes. We work directly with a tier-one integrator rather than through a procurement desk.
Once built, a battery's return is set by a continuous choice: hold capacity for frequency response, or move energy across the price curve. That decision is made thousands of times a day, in several markets at once. Treating it as an operational afterthought is how good assets produce mediocre outcomes.
One asset, several markets. What enters is undifferentiated electricity; what leaves is a set of separately priced services. The asset does not change — the choice of which market to serve changes, continuously.
The team behind this platform has completed the acquisition of a fully developed battery storage project in Sweden. Land agreement, permitting and grid connection were in place at the point of purchase; construction is scheduled through 2026. The transaction was publicly disclosed by the seller, a developer listed on a Swedish exchange.
We say little more about it here, and that restraint is deliberate. Project-level detail — capacity, consideration, counterparties, the ownership chain — belongs in a data room under confidentiality, disclosed in full to qualified counterparties who are entitled to examine it. It does not belong on a public page, where it can only be asserted and not tested.
What we will say is the part that matters. There is a difference between a signed transaction and an announced intention, and the European storage market currently contains a great deal more of the second than the first. Connection queues are full of projects that will never be built. We would rather be measured on the smaller number that were.
These come from grid operators, regulators and industry bodies, not from us. Two of them argue for building. Two of them argue for caution. We think a platform should show you both.
New battery storage installed across Europe in 2025 — a 48% increase on the previous year, and the twelfth consecutive record year. Europe's operational fleet passed 100 GWh for the first time.
SolarPower Europe · European Battery Market Outlook 2026–2030Share of new EU battery capacity in 2025 that was utility-scale — the first year large systems, rather than household batteries, drove the market. Residential installations fell for a second year.
SolarPower Europe · EU Battery Storage Market Review 2025Hours of negative wholesale electricity prices in Germany in 2025, against 457 in 2024. The system was paying to shed power it had no way to hold.
Bundesnetzagentur · 2025 electricity market dataSwedish battery capacity by the end of 2024, up from roughly 80 MW at the start of that year. Prequalified capacity in the FCR-D reserve market rose from under 10 MW to around 600 MW in two years — against a requirement that has stayed below 550 MW.
Solarplaza · Sweden BESS market analysis 2025 — read this one as a warningThe European Union's storage target for 2030. Annual installations are projected to exceed 50 GWh in 2026 and to reach roughly 138 GWh by 2030 — and even that trajectory falls short of what a fully flexible renewable system is modelled to require.
SolarPower Europe · European Battery Market Outlook 2026–2030Increase in net profit from stacking multiple services against a single day-ahead strategy, in a peer-reviewed optimisation study using Swedish operating data under Svenska kraftnät rules. The gap between a battery and a well-run battery is not small.
Journal of Energy Storage · 2025Reported revenue from a Nordic battery running a stacked multi-market strategy, against the same asset held on a single frequency product — measured over a quarter by an operator publishing its results. It is the clearest illustration we know of that the operating decision, not the hardware, is what separates outcomes.
Capalo AI · Zeus VPP performance reports, Finland · 2025 Q2The Nordic system is one of the most technically demanding places in Europe to run a battery, and one of the most transparent. We treat it as the place to prove operating discipline. Central and Eastern European markets are where that discipline should be worth the most as their flexibility markets mature.
HyperStrong ranked among the top three integrators globally by newly installed capacity in 2024, according to the S&P Global Energy 2025 report. Founded in 2011 and listed on the STAR Market of the Shanghai Stock Exchange since January 2025, it reports revenue of RMB 11.61 billion for 2025, up 40.4% on the prior year, and has delivered more than 400 projects.
One distinction is worth stating plainly, because it changes how the relationship should be read: HyperStrong is an integrator, not a cell manufacturer. It procures lithium iron phosphate cells from upstream suppliers and builds the battery management, energy management, power conversion, thermal and enclosure layers around them. Cell-level warranty and cost therefore sit in upstream framework agreements, and the company's position rests on supply-chain leverage, engineering and delivery rather than on cell margin. Multi-source supply is what makes that position durable.
Under the memorandum, HyperStrong acknowledges Rainmaker as a preferred industrial counterparty and works with us as technical partner on joint pipeline assessment and technical due diligence within agreed target markets. Its European build-out — Germany-anchored, now extending into Poland and Central Europe — runs along the same corridor as our own. The arrangement is governed by English law.
The memorandum is non-binding and non-exclusive on both sides. It creates no obligation on HyperStrong to supply, to invest, or to participate in any particular project, and nothing described on this page should be read as a guarantee, a backstop, or a credit enhancement of any kind. Figures relating to HyperStrong are drawn from its exchange filings and public announcements and from third-party industry sources; they describe HyperStrong and are not a representation about any Rainmaker asset.
These are the things we would want to know if we were sitting on the other side of the table.
Every conversation we have starts with what can go wrong: revenue compression as capacity arrives, connection delay, currency, counterparty, the technology risk inside a fifteen-year warranty. If a risk only appears in the appendix, it was not being taken seriously.
Nordic frequency markets rewarded early entrants generously and then, predictably, compressed as capacity arrived. Any asset underwritten on one product is underwritten on a moment. We design for movement between reserve products, balancing markets and energy arbitrage.
We own what we build and we stay with it. Our interest is in how an asset performs in year nine, which is a different business from assembling a portfolio and passing it on.
Structure, related-party arrangements and the provenance of every project are disclosed in full to qualified counterparties at diligence stage. We would rather lose a conversation early than have it unravel late.
We speak with developers, grid engineers, offtakers, operators and long-horizon capital. Detailed information on the platform and its assets is made available to qualified counterparties under confidentiality.
contact@rainmakergroup.io