Solar Savings Trapped in Spreadsheets
The client financed and installed rooftop solar on commercial buildings throughout California. Their products, a power purchase agreement and a PACE loan structure, promised building owners reduced electricity costs and a new revenue stream from tenants. The math worked on paper. In practice, actually billing tenants for their share of solar-offset electricity was a slog.
The building owner would receive a utility bill for the whole property. Figuring out how much each tenant owed meant pulling consumption data from sub-meters, looking up the current rate schedule, applying time-of-use periods and demand tiers, calculating what the bill would have been without solar, then subtracting the solar offset allocated to each tenant. This happened in spreadsheets. It was slow, error-prone, and hard to defend when a tenant pushed back on the numbers.
The client wanted to offer building owners a turnkey solution: install the solar, install the meters, and hand them a platform that handles the rest. No spreadsheets, no manual rate lookups, no chasing down payments. The platform would pull meter data automatically, compute everything in the background, and deposit money in the building owner's account each month.
From Requirements Through Deployment
Sequoia Applied Technologies is a Santa Clara software engineering firm that builds IoT platforms, cloud infrastructure, and enterprise software for cleantech, life sciences, and product companies. This engagement started with a 58 page business requirements document that specified everything from meter hardware to Stripe integration to quarterly report layouts. The scope was a full platform build: backend services, database design, API integrations, web dashboards for three user roles, and automated reporting.
The first phase focused on the data plumbing. The platform needed to ingest readings from eGauge consumption meters and Rainforest HAN communication gateways at 5 or 15 minute intervals, pull solar production data from PV meters, and store everything in a structure that supported the disaggregation calculations. The second phase tackled the tariff engine. California utility rate structures are baroque. Southern California Edison and San Diego Gas & Electric each have dozens of commercial rate schedules with tiered consumption charges, time-of-use periods that shift by season, demand charges based on peak load, baseline allowances that vary by climate zone, and assorted ancillary fees. The platform integrated with the Genability API to pull current tariffs and map them against each tenant's consumption profile.
The third phase built the billing and reporting layer. The system generates invoices, pushes them through Stripe, and reconciles payments. Building owners see a dashboard with real-time solar production overlaid on consumption, per-tenant breakdowns, and historical savings. Quarterly and annual reports roll up the data into PDF summaries showing pre-solar versus post-solar costs, solar offset percentages, and cumulative savings.
Meters, Tariffs, and the Math in Between
The platform sits between IoT hardware on the building side and financial systems on the billing side. Data flows in from meters, gets munged through the tariff engine, and comes out as invoices and reports. The architecture had to accommodate different metering setups across buildings while producing consistent outputs.
Each tenant space gets an eGauge meter at the electrical panel. Meters sample real power at 5 or 15 minute intervals and push readings through a Rainforest HAN gateway to the cloud. For buildings without direct metering, the platform can pull data via UtilityAPI or Green Button API with tenant authorization. The system normalizes readings into kWh consumption and kW demand figures regardless of source.
PV meters like the iTron kV2c track solar generation at the same intervals as consumption meters. The platform pulls production data via API or direct Modbus connection depending on inverter setup. Production is mapped against consumption by time interval to determine how much solar was used on-site versus exported to the grid, which affects net metering credits and true-up calculations.
The Genability integration pulls rate schedules for SCE and SDG&E. The engine handles tiered rates, time-of-use periods with seasonal shifts, demand charges, baseline allowances, and non-bypassable charges. Each tenant's consumption is run through the tariff engine twice: once to calculate the theoretical pre-solar bill, once to calculate the actual post-solar bill. The difference is the savings from solar.
Stripe handles invoicing and payment processing. The platform generates invoices based on disaggregated costs, emails them to tenants, and collects payments on behalf of the building owner. Building owners can set the rate they charge tenants, which might be at utility parity or discounted to share solar savings. The system tracks payment status and flags delinquencies.
The platform supports three user roles with different dashboard views. Admins at the solar financing company see the full fleet of buildings, can onboard new properties, and generate reports across the portfolio. Building owners see their own properties, tenant-level consumption, and financial summaries. Tenants see their usage and statements. Role-based access controls keep each party's data siloed while letting the platform operator maintain oversight.
Automated Billing, Defensible Numbers
Sequoia delivered a platform that closes the loop from meter reading to payment collection. Building owners no longer need to wrangle spreadsheets or manually chase down rate schedules. The quarterly reports show exactly how savings were calculated, which makes tenant conversations easier. The Stripe integration means money moves automatically rather than waiting on manual invoicing and check processing.
For the solar financing company, the platform became a differentiator. They could offer building owners a complete package: financing, installation, and a software system that handles ongoing operations. The platform's reporting also supports the annual true-up process where solar production is reconciled against projections and any over- or under-performance triggers payments between the financing company and the building owner.
The broader pattern here applies to any situation where a shared resource needs to be allocated and billed to multiple parties based on usage. The hard part is getting the data in, applying the right rules, and presenting the results in a way that everyone trusts. Sequoia has done similar work for distributed energy storage systems and EV charging infrastructure where metering, tariffs, and billing intersect.
Common Questions About Commercial Solar Billing Platforms
What is load disaggregation and why does it matter for commercial solar?
Load disaggregation is the process of breaking down a building's total electricity consumption into the portions attributable to each tenant or area. For commercial buildings with rooftop solar, this matters because the solar array generates electricity that offsets the whole building's grid consumption, but individual tenants need to be billed for their share. Without disaggregation, building owners are stuck with spreadsheets and guesswork to figure out who owes what. The platform Sequoia built pulls granular meter data at 5 or 15 minute intervals, maps it against utility time-of-use periods and demand tiers, and produces accurate per-tenant cost allocations that reflect both consumption patterns and the value of solar offset during each billing period.
How does the platform integrate with utility rate tariffs?
The platform integrates with the Genability API to pull current rate schedules for California utilities including Southern California Edison and San Diego Gas and Electric. Utility rate structures are complicated. They include tiered consumption rates, time-of-use periods with different prices for peak and off-peak hours, demand charges based on maximum load during the billing period, baseline allowances that vary by geography and season, and various ancillary fees. The platform maps each tenant's consumption against these tariff structures to calculate what they would have paid without solar, what they actually owe with solar offset, and what the building owner saves. This mapping happens automatically as rate schedules change.
What IoT hardware does the platform support?
The platform was designed to integrate with eGauge electricity consumption meters installed at each tenant's service panel, Rainforest HAN communication gateways that relay data to the cloud, and solar PV production meters like the iTron kV2c. The architecture also supports pulling consumption data via UtilityAPI or Green Button API for buildings where direct metering is not installed. Communication gateways connect to building WiFi or BACnet networks and push readings to the platform backend. The system is designed for flexibility because different buildings have different existing infrastructure, and the platform needed to work with whatever metering equipment was already in place or could be cost-effectively added.
How does automated tenant billing work through Stripe?
The platform integrates with Stripe to handle invoicing and payment collection. Each month, the system generates invoices based on the disaggregated load calculations and sends them to tenants on behalf of the building owner. Tenants pay through Stripe and the funds flow to the building owner. The building owner can set the electricity rate charged to tenants, which might be at or below the utility rate depending on how they want to share solar savings. This automation replaces a manual process where building owners would receive the utility bill, calculate each tenant's share in a spreadsheet, generate invoices by hand, and chase down payments. The platform closes the loop from meter reading to cash in hand.
What reporting does the platform provide to building owners and tenants?
The platform generates quarterly and annual energy reports that show building-wide and per-tenant electricity usage, solar generation mapped against consumption by time period, pre-solar versus post-solar cost comparisons, and cumulative savings. Building owners see a dashboard with real-time solar production overlaid on consumption, visibility into each tenant's usage patterns, and the ability to drill into historical data. Tenants can access a limited view showing their own consumption and statements. Reports are delivered by email and also accessible through the web interface. The quarterly reports include charts breaking down usage by tenant and month, solar generation versus on-site consumption versus grid export, and cost summaries showing what each party owes or has saved.
What kind of companies does Sequoia Applied Technologies work with on cleantech platforms?
Sequoia Applied Technologies is a Santa Clara software engineering firm that works with product companies across cleantech, IoT, life sciences, and enterprise software. Cleantech engagements have included distributed energy storage platforms, EV charging infrastructure firmware, and this commercial solar billing system. The firm handles the full stack from embedded firmware on microcontrollers to cloud backends and web dashboards. For cleantech specifically, Sequoia has experience with utility rate structures, grid interconnection requirements, metering protocols, and the regulatory landscape around energy systems. The team works as an extension of the client's product organization, taking projects from requirements through deployment.