Table of Contents
This renewable energy case study follows a representative freedom-to-operate scenario: a grid-scale battery energy storage developer preparing to ship a next-generation utility system into a field that files patents faster than almost any other in energy. The renewables build-out is enormous — IRENA reports a record 585 GW of new renewable capacity added in 2024 — and every gigawatt of solar and wind needs storage, which is exactly why the storage patent thicket has become so dense. The work below shows how a structured clearance turned a wall of battery patents into a short, actionable list.
The Challenge: A Storage Launch Into a Patent Thicket
Storage is where renewable-energy patenting is most intense. The joint EPO–IEA study Innovation in batteries and electricity storage found that patenting in the sector grew about 14% a year between 2005 and 2018 — roughly four times the all-technology average — with annual international patent families rising from about 1,500 to more than 7,000, over 65,000 filed since 2000, and batteries making up close to 90% of all electricity-storage patenting. The pace has not let up: the EPO’s Patent Index 2024 recorded battery-technology filings rising about 24% year on year.
Our scenario client had designed a utility-scale battery energy storage system with a novel cell-to-rack thermal architecture and a grid-forming inverter control scheme, and planned to sell it in the United States, the European Union, Korea, Japan and Australia. The commercial pull was clear — IRENA’s Renewable Capacity Statistics 2025 put renewables at a record 92.5% of new power capacity in 2024 — and so was the number of incumbents holding live claims. Launching into that field without a freedom-to-operate review is launching blind.
Our Approach
We ran the five-check clearance method the freedom-to-operate analysis service describes, adapted to a storage system. First, claim mapping: we decomposed the product into its patent-relevant features — cell chemistry, cell-to-rack thermal management, module architecture, the battery-management balancing logic, and the grid-forming inverter controls — and read each against the independent claims of the candidate patents rather than their marketing abstracts.
Second, an in-force screen removed expired and maintenance-lapsed references while deliberately keeping pending applications from the major assignees, because a published application can still issue with claims that cover the product. Third, blocking-patent identification narrowed more than 600 live candidate claims to the small set the system genuinely read on. Fourth, a territorial matrix repeated the read for the US, EU, Korea, Japan and Australia, since a patent granted in one market grants nothing in the next. Fifth, for each real blocker we costed a design-around against a licence, and stress-tested the closest claims with a validity screen so a shaky patent was not mistaken for an immovable wall.
What This Renewable Energy Case Study Screened
Triage did most of the work. Of more than 600 live claims that mentioned similar technology, only four mapped cleanly onto the product’s core features: two on the cell-to-rack thermal-management structure, one on a state-of-charge balancing method, and one on a grid-forming control sequence. The remaining hundreds were directed at different chemistries, limited by narrowing features the system did not use, or expired.
Territory changed the picture again. One thermal-management claim was in force only in Korea, leaving the other four target markets clear on that feature. The balancing-method claim was live in the US and EU but looked vulnerable on validity given earlier published art surfaced during the screen. None of this is visible from a raw hit count — it only emerges when live claims are read one by one against what the product actually does. The concentration of storage patents among a handful of Asian cell makers, documented in the EPO–IEA data, meant the candidate set clustered around a small number of well-resourced assignees who defend their claims.
The Outcome
Four blockers is a solvable problem. For the thermal-management claims, engineering re-routed the coolant path to fall outside the claimed structure — a change small enough to make before the enclosure tooling was locked. For the balancing method, the team altered the algorithm to sidestep the claimed sequence while a licence was scoped and held in reserve. The Korea-only thermal claim was handled by sequencing: the system shipped first into the four clear markets while the Korean position was resolved.
The deliverable was not a memo saying “looks fine.” It was a jurisdictional clearance matrix, a ranked design-around shortlist, and a written freedom-to-operate opinion the board could rely on. That opinion matters beyond the launch decision: under 35 U.S.C. § 284 a court can treble damages for willful infringement, and a competent, timely opinion is evidence of the good-faith belief that helps rebut a willfulness finding. In a field where a single storage dispute — LG Energy Solution v. SK Innovation — settled in 2021 for a reported $1.8 billion, that record is not a formality.
What This Means for Similar Matters
Three lessons carry to any crowded-field renewable launch. Start before tooling: every blocker the client cleared was cleared cheaply because the design could still change — the same finding after production would have meant scrapped enclosures. Triage ruthlessly: the value is not in reading 600 patents, it is in finding the 4 that matter and clearing the rest with confidence. And insist on a written opinion, not an email, because only the former builds the good-faith record a board, an acquirer, or a court will credit.
Finally, clearance is not a one-time gate. With battery filings still rising at double-digit rates, new claims arrive every quarter and product roadmaps move toward new chemistries and grid-forming features. A storage freedom-to-operate study should be refreshed when the design changes materially or the launch expands into a new jurisdiction — the matrix is a living document, not a certificate.
Why Storage Disputes Make FTO Non-Optional
The renewable-energy patent wars are not hypothetical. In batteries, LG Energy Solution v. SK Innovation ran through the US International Trade Commission before settling in April 2021 for a reported $1.8 billion — one of the largest battery IP settlements on record. In solar, Hanwha Q CELLS sued JinkoSolar, LONGi and REC across the ITC, a US district court and the Düsseldorf Regional Court over passivation cell technology, and more recent TOPCon and back-contact disputes — Trina Solar v. Runergy in the US, and Maxeon actions in Europe including before the Unified Patent Court — show the litigation moving with each new cell architecture.
The pattern is consistent: as a renewable technology matures and volumes climb, the incumbents that built the early patent walls begin enforcing them against fast-scaling entrants. A developer bringing a new storage or solar product to market is walking into that enforcement environment, which is exactly why a clearance read — run while the design can still change — is the cheapest insurance available.
Data Sources
The market and patent data referenced above comes from:
- EPO–IEA — Innovation in batteries and electricity storage (2020) — Battery patenting grew ~14%/year 2005–2018; annual IPFs rose from ~1,500 to over 7,000; batteries ~90% of electricity-storage patenting.
- EPO — Patent Index 2024 — Battery-technology patent filings at the EPO rose about 24% year on year in 2024.
- IRENA — Renewable Capacity Statistics 2025 — A record 585 GW of renewable capacity added in 2024; renewables 92.5% of new power capacity.
- Jones Day — SK Innovation resolves global patent dispute with LG (2021) — LG Energy Solution v. SK Innovation ITC battery dispute, settled April 2021 for a reported $1.8 billion.
- 35 U.S.C. § 284 — Damages — Authorises enhanced damages up to three times the amount found for willful infringement.
Discuss a Similar Clearance Matter
Planning a renewable-energy or storage launch into a crowded patent field? Tell us the product and the markets, and we will scope the freedom-to-operate study.
Discuss a Similar Clearance Matter
Related PerspireIP work: Freedom-to-Operate Analysis service · How to conduct a freedom-to-operate analysis · FTO case study: clearing an EV battery pack.
Frequently Asked Questions
Is this renewable energy case study based on a real client engagement?
No. It is a representative scenario built from PerspireIP’s clearance method and from publicly verifiable industry data (EPO–IEA, EPO Patent Index and IRENA figures, and public litigation records). The scenario metrics illustrate how the work unfolds; they are not the reported results of a specific named client.
Why is freedom-to-operate so important for renewable energy storage?
Storage is one of the fastest-filing fields in technology — the EPO–IEA study recorded battery patenting growing about 14% a year, with over 7,000 international patent families filed in 2018 alone. That density, plus billion-dollar disputes like LG Energy Solution v. SK Innovation, makes a clearance read essential before a launch.
How many patents does a storage freedom-to-operate study screen?
It varies with scope, but the field is dense: this scenario surfaced more than 600 live candidate claims. Triage then narrows that to the handful — here, four — that genuinely block the product, so the analytical effort concentrates where it changes the launch decision.
Does a freedom-to-operate opinion reduce the risk of enhanced damages?
A competent, timely opinion of counsel is evidence of a good-faith belief that helps rebut a willful-infringement finding, which under 35 U.S.C. § 284 can carry damages up to three times the amount found. In a field with billion-dollar settlements on record, that is a material reason a written opinion earns its cost.