meteocontrol
Its Gridcog revenue assessment for a 10 MWp solar and 10 MWh battery project in Unterallgäu was a key input to the capital value and mortgage value assessment for project financing.
meteocontrol: read the case studyGridcog for investors and funds
Renewable energy investment modelling for investors and funds
Investors and funds test battery energy storage system (BESS) and hybrid project returns by modelling the downside before they commit capital: merchant exposure, offtake terms, degradation and grid limits, interval by interval. Gridcog gives the analysts, developers and advisors behind renewable energy investment decisions one transparent model, from assumption to internal rate of return (IRR).
Key points
1.2x–2x
Lenders typically require a debt service coverage ratio (DSCR) of 1.2x to 2x, higher for merchant-exposed projects (Gridcog, April 2025).
15 years
Battery tolling agreements typically run four to seven years, while revenue floors can support tenors of up to fifteen years (Gridcog, July 2026).
£27m
Sustain Commercial Solar, which models its revenue stack in Gridcog, estimates around £27m of investment secured over the past 12 months (case study, October 2026).
18,000+
Gridcog has modelled more than 18,000 energy projects across 40+ markets.
What do investors need to know before committing capital to a BESS or hybrid project?
The spread of returns, from merchant downside to contracted upside.
Lenders size debt on a conservative banking case and stress-test it. Sponsors and equity investors need the upside case as well. Both depend on how the battery dispatches across markets, interval by interval, which a forecast of price times volume can't show.
Lenders
vsSponsors and equity investors
Main question
Will the project cover its debt in a downside case?
What is the realistic range of returns, including upside?
Revenue case
Independent forecast from a consultant the lender trusts, on a reliance basis
Low, central and upside scenarios, tested against real market volatility
Typical tests
Price or spread discounts, lower availability, faster degradation
Asset sizing, co-location, grid connection and contracting options
Covenant
DSCR of 1.2x to 2x, higher for merchant exposure
Equity share, often 50:50 or more on fully merchant deals
What makes a BESS project bankable?
A revenue forecast that meets a lender's credit committee, prepared independently by a consultant the lender trusts and provided on a reliance basis.
For solar and wind that rested on yield and long-term prices. Battery storage adds a third factor: dispatch simulation with realistic operating parameters, degradation and market participation.
Developers and investors need their own model alongside the banking case. It optimises the design, supports the equity case with low, central and upside scenarios, and tests contracting options, while producing outputs that can be checked against the banking case.
Read relying on renewable energy, battery storage and flex modelling for bankable project financing→How do offtake contracts change battery storage returns?
Each contract moves risk between the asset owner, the lender and the offtaker.
More contracted revenue lowers the DSCR a lender needs and supports more debt, but it gives away upside or control.
Offtake structures
Structure 01 of 04
Tolling agreement (physical swap)
How it settles
Fixed payment; the offtaker sets dispatch
What the owner gives up
Upside and operational control; strict availability obligations
Typical tenor
Four to seven years
Structure 02 of 04
Revenue swap
How it settles
Against the battery's actual net revenue
What the owner gives up
Standardisation: it is bespoke and hard to verify, though basis risk is low
Typical tenor
Bespoke
Structure 03 of 04
Top-bottom spread (TBx) swap
How it settles
Against a daily price-spread index
What the owner gives up
Basis risk if the index outruns the battery
Typical tenor
Varies by market
Structure 04 of 04
Floor or collar
How it settles
Tops up revenue below a minimum; a collar adds a cap
What the owner gives up
Some or all upside above the cap
Typical tenor
Up to fifteen years
Gridcog Energy Analyst Catalina Villaro modelled a 100 MW, four-hour GB battery with a day-ahead swap on its exports at a fixed £100/MWh. Over the first quarter of 2027, the swap narrowed monthly revenue from £13,100 to £22,500 per MW down to £14,551 to £17,304 per MW.
Read battery storage offtake agreements: swaps, floors and bankability explained→Want to see how your project's returns move under each structure?
Model your project in Gridcog →How do investment teams use Gridcog?
Through the analysts, developers and advisors who build the investment case.
They model the project as it will be built and contracted, then show financing partners every step from assumption to IRR.
- ✓
Compare cashflows, IRR and net present value (NPV) across merchant, contracted and hybrid scenarios
- ✓
Rerun a case on a lender's or advisor's own price curves
- ✓
Model degradation, warranties and repowering with capex and opex assumptions
- ✓
Put revenue, financials and key assumptions in one place with the Investment Case Report
- ✓
Inspect every input and interval-level result, so the case can be explained at investment committee
Which investors and advisors rely on Gridcog's analysis?
SUNCATCHER Engineering
EPC contractor for battery projects within the SUNCATCHER Group, Germany and Poland. Reruns scenarios on customers' price curves to answer what each bank wants to see, and produces Gridcog reports in German where banks ask for them.
SUNCATCHER Engineering: read the case study→Sustain Commercial Solar
Models solar, battery storage, trading and capacity market income for its clients and estimates around £27m of investment secured over 12 months.
Sustain: read the case study→Which technologies can investors' teams model?
Standalone and co-located batteries, from short to long duration, alongside solar and wind on a shared connection.
Battery energy storage system (BESS) modelling→Frequently asked questions
Can't see your question?
Get in touch →No. Lenders rely on independent forecasts from consultants they trust, provided on a reliance basis. Developers and investors use Gridcog for their own development-stage and equity modelling: optimising design, testing contracts and building low, central and upside cases. Those outputs can be checked against the banking case and against actual asset performance.
Usually 1.2x to 2x: the project must cover its debt payments plus a buffer. The ratio is higher for merchant-exposed projects and lower for well-contracted ones. Fully merchant BESS financings tend to carry more equity, often 50:50, tighter covenants, higher coverage requirements and reserve accounts to absorb market risk.
A tolling agreement, also called a physical or capacity swap, is a contract where the offtaker rents a share of a battery's capacity and sets its dispatch. The owner receives a fixed payment with high revenue certainty, in exchange for strict availability obligations. Terms typically run four to seven years.
A top-bottom spread (TBx) contract settles against an index of the spread between the highest-priced and lowest-priced hours of the day. The owner keeps operational control but owes the index spread whatever the battery earned, so it carries the basis risk if the battery is offline, degraded or trading elsewhere.
Yes. Teams can model on Gridcog's market data or upload their own price curves, including a lender's or advisor's, and run alternative scenarios on each. SUNCATCHER Engineering uses this to answer the different curves and sensitivities each bank asks for. Compare results with our benchmark projects.
Yes. You can compare the financial and physical effects of warranties and degradation, including cycles per day, efficiency and depth of discharge, and model repowering scenarios with capex and opex assumptions. Dispatch reflects market rules such as bid rounding and headroom and footroom, so degradation follows how the battery actually trades.
Gridcog supports 40+ markets, including Great Britain, Australia, New Zealand and, in Europe, Germany, Spain, Poland, Italy, Portugal, the Netherlands, Belgium and France. The team keeps adding new markets to the platform. See how Gridcog models the GB electricity market and Australia's National Electricity Market (NEM).
Related industries
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The team behind Gridcog
Fabian Le Gay Brereton
Chief Executive Officer & Co-Founder
Previously co-founded Greensense, acquired by ERM Power (now Shell Energy).
Pete Tickler
Chief Product Officer & Co-Founder
Co-founded Greensense and led digital innovation at ERM Power (now Shell Energy).
Genna Boyle
Chief Commercial Officer & Head of EMEA
More than 10 years in energy strategy, trading and renewables, with senior roles at Battery Optimiser and Limejump.
