Solar Stake pools USDC to fund solar on homes. Homeowners sign 20-year contracts to buy the power, or to own the system at the end. That income pays you a fixed monthly rate, on-chain, for the term you choose.
Stakers lend $20,800 of the cost (80%). The $SLR treasury puts in the rest as a cushion and is paid last. "Earns" is after the service reserve; everything left over goes to reserves, then the $SLR equity, then buybacks.
You are the lender. A ring-fenced company owns the panels. The homeowner buys the power. Every step happens in this order.
The roof passes a site survey, then the homeowner picks a 20-year contract: pay per kWh (PPA) or pay a fixed amount and own the system at the end (lease-to-own). Either way, $0 down.
You deposit USDC into a tier and receive an $sSLR certificate: your note, with a fixed rate and a maturity date.
The Vault lends 80% of each system's cost to a dedicated company that owns the panels. The $SLR treasury puts in the other 20%.
Fixed price per watt, paid in three stages against verified milestones. The installer carries insurance and the workmanship warranty.
Homeowner payments, solar credits (SRECs), and any grants or rebates are converted to USDC by a licensed custodian and sent to the Vault. Credits and grants always go to the Vault for the full term, under either contract.
Smart contracts pay your interest first, set aside reserves, and send any surplus to buy back $SLR. No one touches it by hand.
Fixed rates, paid monthly in USDC. Principal returned at maturity. No early withdrawal — but your certificate is transferable to any other verified wallet, so you can sell your position.
Why the caps: shorter notes come due long before the 20-year contracts end, so the SPV repays them from surplus cash and new deposits. Limiting how much of a vault sits in short tiers keeps that manageable. Rates are set per vault when it opens and never change for an open vault.
Each month USDC arrives and the contract runs this sequence. Stakers are always first. The token is always last.
If a rooftop earns more than expected, stakers still get their fixed rate. The extra goes to reserves and the token. If it earns less, reserves absorb it before stakers feel anything.
One typical DC rooftop. Change any assumption and the whole model moves; here is what we assume and why.
Total cash over 20 years is about $82,000 on a $26,000 system. Stakers receive about $42,000 of that in interest and principal. The rest funds reserves, the $SLR equity return, and buybacks. A $5M vault funds roughly 190 DC homes, about 1.5 MW.
| Assumption | Value | Why |
|---|---|---|
| Production | 1,250 kWh per kW per year | Typical for the DC area; fades 0.5% a year as panels age. |
| PPA rate | 17¢/kWh | Below DC retail (roughly 20¢). National PPA range is 16–20¢. Fixed for the term. |
| SREC value | $400 per MWh, declining 3%/yr | DC's solar credit market is the strongest in the country and drives most of the return. Prices follow a legislated step-down, so we model decline, not a flat line. |
| Service reserve | $20/kW/yr + $250/yr inverter fund | Inverters typically need replacing once in 20 years, around year 10–12. |
| Credits and grants | SRECs to the Vault; tax credits and grants assumed zero | SRECs, grants, and rebates are assigned to the Vault for the term under both contract types. The base case assumes no tax credits or grants; if captured, they go to reserves, then buybacks. |
| Defaults | Covered by reserve | Electricity is the bill people pay first. The default reserve is sized by governance per vault and disclosed before it opens. |
Stakers earn the interest. The homeowner earns the savings — and, if they choose, ends up owning the system.
Uses the PPA rate from the calculator at the top. Year-1 savings are modest on purpose; the value is 20 years of protection from rate increases.
Survey first, signature second, then money. Stakers can see exactly what they funded.
Address, 12 months of utility bills, and photos of the roof, main electrical panel, and meter.
An approved EPC completes a visual survey: shade analysis, roof age and condition, panel capacity, structural notes.
Clear pass/fail rules. Declined homes get the reason and what would fix it — a new roof, tree work, a panel upgrade.
Approved homeowners sign the 20-year PPA or lease-to-own agreement, including assignment of credits and grants to the Vault. Nothing is funded and nothing is built until this signature is on file.
Every party has one job, and any installer can be replaced.
Holds staker USDC, lends it to the SPV, runs the monthly waterfall. Code, audited and public.
One per vault. Owns the hardware (until a lease-to-own transfers title at year 20), holds the contracts and credit assignments, collects payments through a licensed custodian, owes the Vault. If it fails, nothing else is touched.
Pass licensing, insurance, and workmanship review before they can bid. Build under a fixed-price master agreement; can be removed by governance vote.
The goal is every rooftop in the country. Each state gets its own vault, its own SPV, and its own disclosed assumptions, because the economics differ everywhere. Four pilots first.
Small rooftops (8 kW), the strongest solar-credit market in the country. This is the base case modeled above.
Bigger roofs (16 kW), retail rates that have climbed past 24¢ in parts of the state, a steady SREC market, and MEA grants that cut the equity needed per home. Credits are smaller than DC's, so the Maryland vault lends 70% per rooftop instead of 80% and targets high-rate utility territories first.
Retail rates above 30¢ mean a 20–24¢ PPA saves homeowners real money with no credits at all. Batteries will be in scope, so a separate model and EPC price.
Few installers, low rates, and rules that push back on third-party power sales — so lease-to-own is the only contract offered there. Hardest market on purpose: if it works here, it works anywhere.
After the pilots, states open in the order their economics and rules allow. Where third-party power sales are restricted, only lease-to-own is offered.
Fixed rates are only as good as the cash behind them. These are the real risks, in the order we worry about them.
In DC, SRECs are most of the return. We model a 3%/yr decline; a policy change could be sharper. The 1.5× worst-year coverage and the reserves are the buffer.
Rare for electricity, but real. The default reserve covers it; beyond that, the SPV can remove a PPA system and re-deploy it, or enforce its lien on a lease-to-own system.
There is no early withdrawal. Your exit is selling your $sSLR to another verified wallet, and there may not be a buyer at the price you want.
The service reserve and the EPC's workmanship warranty cover most of it. A bad batch of panels across a whole vault would strain both.
Securities rules, state solar rules, and stablecoin rules all move. Each vault launches under the law as it stands, with counsel, and discloses which exemption it uses.
Contracts are audited before any vault opens, and the SPV's treasury is a multisig. Code can still fail. Audit reports are published.