A PG&E demand charge is a monthly fee based on your peak electricity consumption — measured as the highest average power draw during any single 15-minute interval in your billing period. Under the B-19 rate schedule, this charge is approximately $28–38 per kilowatt per month.

For example: if your facility hits a peak draw of 250 kW for just 15 minutes at any point during the month — even once, even at 2 AM — you pay a demand charge of 250 × $28 = $7,000 for that entire billing cycle. Demand charges typically represent 35–45% of a commercial facility's total electric bill.

Cold storage facilities have load characteristics that create frequent, predictable demand spikes. Refrigeration compressors draw 40–60% above their steady-state consumption during startup. Multiple evaporators running defrost cycles simultaneously can spike demand substantially. These events are difficult to prevent through operational scheduling alone because they're driven by the refrigeration system's own control logic.

The good news: because these events are predictable and controllable, they're exactly the kind of load that a well-configured EMS can reschedule — moving defrost cycles to solar production hours and staggering compressor restarts to prevent simultaneous inrush.

NEM 3.0 (Net Billing Tariff) replaced NEM 2.0 for all new California solar interconnections after April 15, 2023. It reduced compensation for exported solar energy by approximately 75%, making solar-only systems significantly less economical. However, PG&E's on-peak avoided cost rates during summer evenings (4–9 PM) can reach $0.45–0.52/kWh.

The correct NEM 3.0 strategy is to avoid it altogether by self-consuming as much solar as possible, and dispatch batteries during on-peak hours to reduce demand and grid draws. While still being grid-tied, non-exporting systems will keep all the power within your facility.

Demand Shield attacks demand charges through three coordinated mechanisms. First, the solar array covers daytime facility load and charges the battery during off-peak production hours, reducing the baseline grid draw.

Second, the battery discharges during PG&E's 4–9 PM on-peak window, when demand charges are highest — preventing the facility from drawing high power from the grid during the billing period's most expensive interval.

Third — and this is what most solar companies skip — the EMS reschedules controllable load events. Cold storage defrost cycles are moved to solar production hours (10 AM–2 PM), when the solar array absorbs the demand spike. Compressor restarts after defrost are staggered with a 2–3 minute delay between units, converting a 250 kW spike into a 120 kW ramp. These operational changes add 10–15% more demand reduction on top of what the battery alone achieves.

No — and any contractor who says otherwise isn't being straight with you. Solar generates meaningful power for 5–6 hours per day. Cold storage runs continuous refrigeration loads around the clock — typically 100–300 kW depending on size and temperature range. Full energy independence is not physically or economically achievable for a 24/7 refrigeration operation with current technology.

The correct goal is maximum cost reduction, not energy independence. Demand Shield covers your highest-cost exposure — on-peak energy and demand charges — while the grid handles overnight load at off-peak rates. This achieves 70–80% total bill reduction at a payback of 2–5 years.

A NorCal cold storage facility on PG&E's B-19 rate schedule typically pays $25,000–$65,000 per month in electricity. With a properly sized Demand Shield system — typically 800–1,500 kWh of BESS paired with 350–500 kW DC solar — facilities typically save $18,000–$35,000 per month, or $215,000–$420,000 per year.

After California's SGIP battery rebate ($250/kWh for commercial systems) and available federal incentives, net system cost is typically $700,000–$1.6 million — yielding a simple payback of 2–5 years. Request a free analysis for a facility-specific estimate.

Typical timeline is 6–9 months from signed contract to Permission to Operate. Engineering and design: 2–3 weeks. Permitting and PG&E interconnection application: 8–14 weeks. Equipment procurement: concurrent with permitting. Physical installation: 3–6 weeks. Commissioning and EMS configuration: 1–2 weeks. PG&E interconnection approval and Permission to Operate: 4–8 weeks.

The most variable element is PG&E's interconnection queue — in high-demand areas like Sacramento and the Bay Area, this runs 10–16 weeks. SGIP application is filed during the design phase and does not extend the timeline.

VoltBlock offers LFP on request — it's a proven, cost-effective chemistry. But for cold storage environments, sodium-ion batteries are exceptionally safe, perform reliably in extreme temperatures, and can discharge deeply and rapidly without wearing out. They're built to last more than 10,000 full charge-discharge cycles with no reduction in performance over time. Sodium-ion batteries offer advantages LFP cannot match: genuine thermal inertness (no thermal runaway under any condition) and a modular distributed form factor that eliminates the need for a centralized battery room.

For cold storage operators, the most decisive argument is fire safety. LFP batteries can experience thermal runaway under abusive conditions. Sodium Ion cannot. For a facility storing perishable inventory worth hundreds of thousands of dollars, that distinction matters more than any spec sheet comparison.

SGIP (Self-Generation Incentive Program) is California's statewide cash rebate for commercial BESS, administered by the CPUC and available to PG&E customers. The current Large-Scale Storage General Market rebate is $250 per kilowatt-hour of usable battery capacity. A 1,200 kWh Demand Shield system receives approximately $300,000 in SGIP rebates.

SGIP operates on a step-funded structure — rebates decrease as steps fill, so early applicants receive better rates. Non-residential systems have no size cap. VoltBlock files SGIP applications as part of every project at no additional cost. Applicants must enroll in a qualified Demand Response program and complete 52 annual discharge cycles to maintain rebate eligibility.

The single most valuable document is 12 months of 15-minute interval data from your PG&E account (Green Button export). This shows every demand event, your TOU consumption pattern, and exactly which 15-minute windows have been setting your demand charge. Log in at pge.com → My Energy → Energy Use Details → Export → 15-minute intervals → last 12 months → Download CSV.

For a preliminary estimate, VoltBlock needs your facility type, square footage, NorCal location, and available roof area. Submit your interval data for a full analysis at no cost.