One unit, one voucher, one question.

Whether a CORE-subsidised 540 kW mobile battery can be placed into the California rental market at a rate that services the financing. This page sets out what is known, what is estimated, and what is not yet established.

$560,000Estimated purchase

$280,000CORE voucher

$280,000To finance

50%Subsidised share

The CORE voucher

California's Clean Off-Road Equipment Voucher Incentive Project, funded by CARB and administered by CALSTART.

CORE is a voucher programme, not a competitive grant. There is no proposal and no scoring panel. The equipment must be on CORE's published catalogue, and a CORE-approved dealer submits the voucher request on the purchaser's behalf. The eBESS699-540-01 is listed under Mobile Ground Power Units at a $280,000 voucher.

The voucher is formulaic

Across the twelve mobile ground power units catalogued, eleven pay within 1% of $400 per kWh. The twelfth — a 2.3 MWh unit — pays $300,000, which is the programme cap.

Unit	kWh	Voucher	$/kWh
Cat XES120	128	$51,000	$399
Ampd 400	430	$172,000	$400
Coulomb eBESS528	528	$210,000	$398
Coulomb eBESS699	699	$280,000	$400
Coulomb 2.3 MWh	2,300	$300,000	$130

The $300,000 cap binds at 750 kWh. At 699 kWh the eBESS699 is the largest unit on the catalogue still collecting the full rate — every kWh above 750 is unsubsidised.

Conditions that travel with the voucher.

Purchaser must show one year of prior California business operations.
Equipment operates exclusively in California for three years.
Minimum 200 usage hours per year, averaged over the three years.
Activity reports filed throughout the period.
Renting the unit out is permitted — the lessor stays the legal purchaser and carries compliance for the full term. Each lease must spell out every CORE commitment the renter takes on.
Resale within three years requires prior written CARB approval, or a prorated share of the voucher is forfeited.
The purchaser cannot act as its own dealer.

Capital

Equipment — Coulomb eBESS699-540-01 (estimated)	$560,000
CORE voucher	−$280,000
Net capital required	$280,000

Purchase price is an estimate. Coulomb publishes no pricing and does not list this configuration publicly; a written quote is outstanding. Commercial containerised storage broadly runs $400–800/kWh installed, with mobile units at the upper end — $560,000 sits inside that band at roughly $800/kWh. Delivery, commissioning, insurance and transport equipment are not included above.

What the unit has to earn

Debt service on $280,000, and the day rate required to cover it at different utilisation levels.

Term on $280,000 at 8%	Monthly payment
3 years	$8,775
5 years	$5,678
7 years	$4,363

Break-even day rate — 5-year term ($5,678/month)

Utilisation	Rental days / month	Day rate to break even
30%	9	$631
50%	15	$379
70%	21	$270
90%	27	$210

Debt service only. Excludes insurance, transport, maintenance, charging energy and any operator cost. Break-even on the business is higher than break-even on the loan.

The number that decides this is not in this document.

No day rate has been established. Mobile BESS rental rates are not published by any operator, and none has been quoted to PlugRig. The table above states what a rate would have to be — it does not assert what the market pays. Until a rate is confirmed in writing by a customer or a rental house, every revenue figure downstream of it is unfounded.

The fastest way to obtain it: request diesel generator day rates from Sunbelt or United Rentals as a floor, and ask what they would pay for a battery unit of this rating.

Target market

These are targets, not customers. No company named below has been approached, quoted or committed. They are listed because a structural reason exists for them to want this equipment — not because a pipeline exists.

Equipment rental houses — fastest route to utilisation

Sunbelt Rentals held a multi-million-dollar mobile battery distribution agreement with Moxion Power; Moxion ceased operating in 2024, removing supply from the California market while the demand and the sales channel remained. Sunbelt also runs a dedicated Film & TV division. United Rentals and Herc Rentals (owner of Cinelease) sit behind them. Renting into an existing fleet trades rate for immediate utilisation and no sales or logistics burden.

Film and television — highest day rate

Production services companies supplying power to Los Angeles shoots. Studio net-zero commitments push their vendors toward batteries, and a lost shooting day costs far more than the power.

EV fleet charging — best contract length

California depots hold vehicles that arrived before their utility service did; interconnection commonly runs two to five years. Operators building this infrastructure in the Bay Area include WattEV (Port of Oakland), Forum Mobility, Terawatt Infrastructure, EV Realty and Zeem Solutions. Transit agencies and school districts with grant-funded electric buses face the same gap. These are multi-month placements rather than day rentals.

Ports, construction, outage response

CARB's At-Berth Regulation creates compliance-driven shoreside demand at Oakland and Richmond. Construction is the steady base between higher-value placements. Planned power shutoffs create episodic demand at premium rates during fire season.

Open items

Each of these can invalidate part of the case above. None is resolved.

Eligibility. Whether CORE will voucher a mobile ground power unit for a rental-fleet use case, and whether the intended deployments qualify. Unconfirmed with CALSTART.
Purchase price. $560,000 is an estimate. No written quote from Coulomb.
Rated output. 540 kW is read from the model designation, not a datasheet.
Voucher cap per applicant. Unknown whether CORE limits vouchers per applicant or per year — material if more than one unit is contemplated.
Secondary cost cap. CORE vouchers are typically also limited to a percentage of incremental cost. If that binds first, the payout is below $280,000.
Day rate. Not established. See above.
UL 9540 listing and 9540A test data. Determines how straightforward each customer's fire-code approval is. Not published on the CORE catalogue.
Siting. NFPA 855 separation distances and local fire marshal approval apply at every deployment; marine and dockside placement carries additional constraints.
Funding window. CORE heavy-duty funding was stated as reopening Fall 2026; current status to be confirmed by phone.