San Diego Infrastructure Underwriting: Converting Rising Utility OpEx into Balance-Sheet Value with Rooftops Into Revenue™
- Tony Millan
- 13 minutes ago
- 6 min read
San Diego property owners are underwriting a more complex operating environment. SDG&E rate pressure is increasing the importance of energy expense control, while demand charges expose multifamily and commercial assets to short-duration load spikes that can materially affect monthly operating costs.
For owners of multifamily properties with 20 or more units, mixed-use buildings, commercial centers, offices, and other master-metered assets, utility expense should be evaluated as an infrastructure line item: not simply as a bill to be reduced.
The relevant question is:
Can the property convert a volatile operating expense into a controllable margin asset that supports NOI, valuation, and portfolio scalability?
That is the purpose of Utility Margin Capture and the infrastructure strategy behind Rooftops Into Revenue™.
SDG&E demand charges create an underwriting issue beyond kilowatt-hours
SDG&E business customers may pay for both energy consumption and the rate at which electricity is consumed. Consumption is measured in kilowatt-hours, while demand is measured in kilowatts.
The distinction matters because a property can have moderate monthly energy consumption while still creating a significant demand charge through a short-duration peak. SDG&E explains that demand charges may be based on the highest usage recorded during a 15-minute interval. The relevant peak may occur when HVAC systems start simultaneously, elevators operate during a concentrated period, pumps cycle, or commercial equipment comes online.
SDG&E identifies several demand components, including:
Non-coincident demand, which can occur at any time of day
On-peak demand, measured during designated seasonal on-peak periods
Generation demand, associated with on-peak generation requirements
The SDG&E business demand guide provides the utility’s definitions and examples. Current SDG&E commercial time-of-use periods place on-peak usage in the late afternoon and evening, when building loads may remain active while solar production is declining.
For underwriting purposes, this means a property’s energy profile cannot be evaluated using annual kWh alone. A financeable analysis requires interval-level assumptions, tariff accuracy, peak-load mapping, and a clear dispatch strategy for battery storage.
Utility Margin Capture begins with a tariff-specific baseline
A credible San Diego infrastructure model starts with the existing utility configuration.
The analysis should identify:
Whether the property is master-metered, partially master-metered, or individually metered
Which meters serve tenant spaces, common areas, parking facilities, amenities, and building systems
The applicable SDG&E customer class and tariff
The property’s monthly and annual demand history
The timing and duration of its highest load intervals
The portion of utility expense paid by the owner versus tenants
Existing electrical capacity, transformer constraints, and interconnection requirements
Multifamily properties may also have legacy service arrangements. SDG&E’s published rate materials identify certain multifamily schedules as closed to new customers, which means existing properties and new developments may not have the same tariff assumptions.
Underwriting should therefore avoid applying a generic commercial rate to every asset. The correct model must use the property’s actual service configuration and the current tariff schedule available through SDG&E’s total electric rates library.
This baseline separates the reducible portion of utility expense from fixed charges and other costs that remain after infrastructure deployment.
Battery storage targets the margin created by demand charges
Solar generation can reduce purchased energy during periods of production. Battery storage addresses a different part of the cost structure: timing, peak demand, and dispatch control.
For a San Diego multifamily or commercial property, a properly sized battery may be modeled to:
Reduce non-coincident demand peaks
Reduce on-peak demand exposure
Shift stored energy into late-afternoon and evening periods
Capture midday production that would otherwise have lower value
Provide limited backup support for designated building loads
Improve operating predictability during periods of grid or rate volatility
The battery’s value is not determined solely by its nameplate capacity. It is determined by how effectively its dispatch strategy interacts with the property’s load shape and tariff.
A battery that is oversized relative to the property’s demand profile can weaken project economics through unnecessary capital cost. A battery that is undersized may fail to control the intervals that drive demand charges. Underwriting must evaluate power capacity, usable energy capacity, degradation, round-trip efficiency, operating limits, replacement reserves, and controls.
Financing structure determines how value appears in the pro forma
The infrastructure can be financed through ownership, a power purchase agreement, or a hybrid structure. Each model produces a different treatment of capital, operating expense, and risk.
Ownership
Under direct ownership, the property owner funds or finances the system and retains the associated operating benefits. The underwriting focus includes:
Total installed cost
Debt service or capital allocation
O&M and replacement reserves
Incentive and tax treatment
Net utility expense reduction
Expected useful life and residual value
Ownership can provide greater long-term control, but it requires disciplined capital budgeting and technical diligence.
Power purchase agreement
A PPA can reduce upfront capital requirements by allowing a third-party infrastructure owner to develop and operate the system. The property purchases energy under a contracted pricing structure.
The underwriting must compare:
Contracted energy price
Escalator assumptions
Remaining utility purchases
Demand-charge savings retained by the property
Term, renewal, and buyout provisions
Roof access and property transfer requirements
A PPA should not be evaluated as a simple replacement for the utility bill. The relevant analysis is the net margin impact after contracted payments, residual utility costs, O&M responsibilities, and demand-charge treatment.
Hybrid structures
Hybrid structures may combine owner-owned assets with third-party financing or separate solar generation and battery storage economics. This can be useful where the property’s generation opportunity and demand profile require different capital strategies.
The objective is not to maximize system size. It is to optimize the relationship between deployed infrastructure, operating margin, and balance-sheet constraints.
NOI and cap-rate impact require conservative assumptions
If the owner pays the affected utility expense, stabilized savings may flow directly into NOI after accounting for financing, O&M, insurance, taxes, and other project costs.
The basic valuation relationship is straightforward:
Incremental asset value = stabilized NOI improvement ÷ market capitalization rate
The underwriting challenge is determining which portion of the modeled benefit is durable enough to capitalize.
A conservative model should distinguish between:
Utility expense reduction
Demand-charge reduction
Energy arbitrage
Backup or resilience value
Tenant-facing benefits
Potential ancillary revenue
Financing costs
Maintenance and degradation
Regulatory and tariff risk
Owners should avoid capitalizing gross utility savings. The appropriate figure is the stabilized, net operating benefit supported by the selected financing structure and a defensible operating model.
For tenant-paid utilities, the value pathway may be different. Benefits may appear through stronger amenity positioning, lower common-area expense, improved leasing economics, or reduced exposure to utility volatility. These impacts should be underwritten separately rather than automatically treated as direct NOI.
Portfolio scalability is a core part of the investment case
A single-property project can demonstrate technical and financial performance. A portfolio program can create a repeatable infrastructure platform.
For owners with multiple multifamily or commercial assets, portfolio underwriting should establish a standardized process for:
Address-level site screening
Roof and structural review
Utility service classification
Interval-load analysis
Battery dispatch modeling
Interconnection planning
Financing selection
Construction management
System activation and performance monitoring
This approach allows asset managers to rank properties by Utility Margin Capture potential rather than by roof size alone. A building with a smaller roof but substantial demand-charge exposure may produce more margin value than a larger rooftop with limited owner-paid load.
Portfolio deployment can also improve procurement, reporting, maintenance coordination, and financing consistency. The result is a scalable infrastructure program aligned with capital planning and asset-management priorities.
Rooftops Into Revenue™ positions energy as an infrastructure layer
Rooftops Into Revenue™ is built around a different underwriting premise: energy infrastructure can be designed to improve asset performance, not merely to reduce a monthly bill.
For San Diego owners, the strategy connects:
SDG&E tariff analysis
Demand-charge control
Battery storage
Electrical upgrades
Structured financing
NOI expansion
Expense-ratio compression
Portfolio-level deployment
The system design must remain property-specific. There is no universal battery size, tariff assumption, financing structure, or valuation adjustment that applies to every asset.
The correct first step is an address-level feasibility screen that identifies the property’s physical and financial potential. The Solar Energy Estate Report (SEER) is designed to support that initial evaluation without requiring owners to begin with a manual utility-bill submission.
Owners, operators, and investment groups evaluating San Diego assets should treat energy as a controllable infrastructure category within the broader property pro forma. Under the right conditions, Utility Margin Capture can convert rising utility OpEx into a more stable operating platform: supporting NOI, margin resilience, and long-term balance-sheet value.
Save On Solar Now is a national energy infrastructure firm focused on helping multifamily and commercial property owners convert utility expense into structured revenue. Through its Rooftops Into Revenue™ and Utility Expense Repositioning strategies, the firm designs and deploys solar generation and battery storage systems that strengthen asset performance and improve long-term operating stability.
Learn more about Rooftops Into Revenue™.
Phone: (858) 400-3524
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