Residential Utility Program Savings
iSolar offers a utility-tested, proven solar-powered retrofit attic ventilation solution to help reduce system wide peak demand caused directly by residential AC load by approximately 20%.
iSolar’s solution reduces energy consumption, lowers homeowner electricity bills, prevents mold and extends roof and HVAC system component lifespans.
Summary Business Case Factors for LDCs and TX Corps
iSolar’s independently tested, simple, retrofit, patented technology reduces AC load by 20%
Proven solar ventilation technology evacuates hot attic air, directly relieving in-home AC demand at coincident peak times
Across North America, increasingly summer peak demands pose outage risks to many utilities and control areas
Reducing AC power usage lowers residential power costs and extends TX and DX equipment lifespan
Highly positive, cost-effective, economic utility-scale solution reduces LDC peak demands via broad implementation via conservation programs
Avoids/defers expensive peak generation facility construction and operation
LDC installations are undertaken in a few days and weeks to quickly relieve peak demand grid stress (as opposed to the many months and years required for large scale, high cost, peak generation projects)
iSolar Solutions Value
iSolar Solutions has concerned itself with the issue of Escalating Demand Growth, and that Peak demand and energy forecasts have jumped and are at their highest levels in decades. We have no control over the retirement of generators or the ability to dispatch resources, but we can have an impact on the baseline energy and demand consumption in residential buildings, and their air conditioning demand on the grid. We have proven, through extensive testing and third-party verified studies, that our solar powered ventilation solutions deliver incredible energy and non-energy benefits to homeowners and direct energy benefits to utilities that want to achieve grid relief through residential program measures.
In the summer of 2024, iSolar conducted an energy and demand impact study in the Golden Horseshoe area of Southern Ontario. Through third-party independent verification, the data showed a visible shift in electricity consumption pre to post-installation as follows:
Independent Test Results on the Retrofit iSolar FLEXLine Attic Fans have shown:
- The data showed a visible shift in electricity consumption pre to post installation
- The average home reduction was 20% of HVAC cooling electricity in the measurement period
- This normalizes to 576 kWh reduced consumption or 6% of the average Oakville Hydro residential customer (OEB,2023 = 8,742 kWh)
- The average demand reduction during the IESO peak period is 0.3594 Kw* (20% savings)
- The average attic temperature reduces by 3.5°C (38.3 °F), to a maximum of 10°C (50°F) reduction
- There were several hours in which attic temperature matched external temperature
- AC Systems had an average 16% reduction in peak period* run hours, with 10% reduction overall
- Reduction of 0.139 tonnes of CO2 – just accounting for avoided emissions from gas-fired power plants. Savings are much more when consider potential savings from extending life of insulation, shingles & AC.
- High levels of participant satisfaction and ease of external retrofit installation.
- Strong performance with TRC estimate of 2.8 along with ‘set and forget’ nature (no homeowner behavioural changes required).
- Minimizes Smart Thermostat Opt-Outs during peak events
* Based upon summer peak of 1 pm -7 pm for June, July, August.
- 300,000 homes with AC is 107.8 MW peak reduction and 172,800 MWh consumption reduction and 41,700 tonnes CO2 equivalent reduction
Utility Business Case
Background
Utilities are faced with incredible challenges in the coming years considering system capacity and growing load forecasts and unpredictable weather conditions. In fact, in 2024 we saw record heat across North America impacting the entire grid. NERC’s 2024 Long Term Reliability Assessment (2024 LTRA) identifies trends, emerging issues and potential risks to the bulk power system over a 10-year horizon, and in 2024 it identified the mounting reliability challenges the utility industry is facing – supporting energy growth, managing generator retirements, and removing barriers to resource and transmission development.
The reality is that in Canada there are four Provinces identified to be at Elevated Risk for energy resource shortfalls in the coming years and they are as follows:
- Saskatchewan – 2026
- Ontario, British Columbia – 2027
- Manitoba – 2028
In the United States the scenario is similar particularly in the Midwest. These are the Independent System Operators that are at Elevated Risk for energy resource shortfalls:
- MISO, SPP – 2025
- PJM, ERCOT, NPCC New England – 2026
- SERC East, WECC CA/MX – 2028
Generally speaking these shortfalls are due to these three issues:
- Accelerating Retirements – Resource needs to meet escalating demand growth are threatened by the current pace of generator retirements
- Escalating Demand Growth – Peak demand and energy forecasts have jumped and are at their highest levels in decades
- Declining Dispatchable Resources – Replacement resources projected over the next decade are more weather dependent and lack key reliability attributes
Program Cost Effectiveness
Additionally, we have tested iSolar Solutions solar attic ventilation systems in Texas where we have gained an entry in Version 12.0 Volume 4.0 Measurement and Verification Protocols of the Texas Technical Reference Manual created for the Public Utility Commission. Our testing was instrumental in creating this entry for Solar Powered Attic Ventilation Fans in Section 2.4.4 as a deemed savings calculation. The summary is as follows:
Solar attic fans increase the extraction rate of accumulated hot air in attics during the cooling season. Solar attic fans introduce no new electrical load to the home since they are powered by an attached photovoltaic (PV) panel. They save energy by reducing the load on air conditioning equipment, cooling the conditioned space directly underlying the attic, and by reducing heat exchange with supply ducts located in the attic when present.
Deemed savings are provided for a reduced air conditioning load.
Note: This measure was developed with limited savings information for Texas; therefore, solar attic fans should be implemented with the expectation of a savings methodology update in future TRMs as Texas-specific field information becomes available. This measure will be reconsidered on an annual basis. If sufficient M&V data is provided, this measure may be incorporated into Volume 2 as a fully deemed measure.
Eligibility Criteria
The measure applies to existing homes with central- or mini-split-electric-refrigerated air conditioning. Ineligible applications include new homes, homes with tile roofs, homes with metal roofs, and evaporatively cooled homes. Customers participating in hard-to-reach or low-income programs are also eligible to claim cooling savings for homes cooled by one or more room air conditioners by applying an adjustment factor to the provided deemed savings. Solar fans must have an automatic low-temperature shut-off to ensure cold outside air is not drawn into the attic during the heating season.
Baseline Condition
The baseline condition is an existing home with refrigerated air and a vented attic.
Deemed Energy and Demand Savings by Climate Zone
Measure Life and Lifetime Savings
The estimated useful life (EUL) of a solar attic fan is closely related to its motor. The US DOE Advanced Manufacturing Office’s Motor Systems Tip Sheet #3 suggests motors should last approximately 35,000 hours. The average annual hours of operation for solar attic fans across the Texas TRM zones is about 2,300 hours. Accordingly, the EUL for solar attic fans in Texas is estimated to be 15 years. iSolar Solutions motors are IP68 certified with waterproofing and are rated for 50,000 hours so this EUL could potentially be longer.
In the Ontario summer study discussed in the previous section, based upon IESO EM&V Protocol Version 4 – Peak time – 1 pm -7 pm for June, July, August the calculations and assumptions can be summarized as follows:
Strong performance with TRC estimate of 2.8 along with ‘set and forget’ nature (no homeowner behavioural changes required).
Model of 300,000 homes with Centralized Air Conditioning can yield 107.8 MW peak reduction and 172,800 MWh consumption reduction which equals 41,700 tonnes CO2 equivalent reduction.
Conclusion
Utility programs need new measures that address both shell and mechanical systems of residential buildings. Solar attic ventilation systems like iSolar Solutions FLEXLine present an opportunity to deliver cost effective energy and non-energy benefits to residential utility customers. These studies conducted by iSolar Solutions and third-party verified by groups like TetraTech help pave the way for utilities to implement ratepayer funded direct install or rebate driven solar attic fan measures into the market. In scale, this measure is proven to reduce peak demand and save energy while improving comfort and extending the life of air conditioning and roof system components. For more information and details about these studies or to setup a meeting to discuss this measure within the context of a program design please contact Steve Alexander at [email protected] or call (844) 684-7723 x102.
"We are grateful that when they installed the sensor in the attic, they noticed an area of black mould. We had it remediated the following week and increased our insulation at the same time. We have noticed a huge difference in the temperature in the upstairs bedrooms with the addition of the fans and the insulation. The air conditioner can now effectively cool the upstairs just as well as the main floor. We have been trying to make this happen for years, so thanks!!"
Retrofit Solar Attic Fan can help with Peak Demand shortfalls
Scorching summer has Ontario electricity usage hit highs not seen since 2013
Global News - Sept 2nd 2025
The scorching summer of 2025 has led to levels of electricity usage not seen in more than a decade in Ontario.
The Independent Electricity System Operator (IESO), which manages Ontario’s power system, told Global News that this summer has been one for the record books.
2025 Summer Reliability Assessment
NERC’s
NERC’s 2025 Summer Reliability Assessment (SRA) finds an elevated risk of supply shortfalls during wide-area heat waves and abnormal weather conditions like those that have occurred in recent summers. As a result, system operators in many parts of North America could face challenges meeting peak electricity demand. Reserve shortages can occur during a range of conditions that include above-normal electricity demand, periods of low wind and solar output, and wide-area heat events that disrupt available transfers and generator availability. New resource additions—primarily solar and some batteries—are helping to meet surging load growth that continues to strain resources. However, these additions are offset by ongoing generator retirements and introduce more complexity and energy limitations to the resource mix.
2024 Long Term Reliablity Assessment
NERC’s
NERC’s 2024 Long Term Reliability Assessment identifies reliability trends, emerging issues and potential risks to the bulk power system over a 10-year horizon. This year’s report points to the mounting reliability challenges that industry is facing — satisfying escalating energy growth, managing generator retirements and removing barriers to resource and transmission development. Recommendations to address reliability concerns include managing generator deactivations, enhancing future LTRAs with more expansive energy risks analysis, streamlining siting and permitting, promoting natural gas-electric system coordination and ensuring essential reliability services are maintained.
Testing Results
iSolar’s Technology
Summer 2024
Models used for test were smaller retrofit solutions – 20W106-FLEX & 50W108-FLEX (two per home).
Why iSolar Retrofit Attic Ventilation Solution:
Electricity ratepayers will benefit from reduced residential peak-time electricity costs.
In winter months attic ventilation solution helps to prevent ice damming.
This simple solution is an enabler to a healthier home by reducing the possibility of mildew, mold and harmful gases in the attic and crawlspaces. The attic fan increases home comfort in summer months and health security for residents by balancing out the AC and air quality breathing environment.
The iSolar-powered ventilation solution being deployed is backed by over 10 years of research and testing. The research results specifically address energy efficiency and carbon emissions, amongst many other critical environmental and health benefits to residents.
Exclusively uses solar to power the unit to smartly match coincident peak power demand on the grid and reduce AC run time by 16% during peak – System safer from ‘brown outs’.
Helps to support industry standard of proper air exchange rates of 6-10 times per hour for healthy level of air circulation / ventilation. .
A sustainable solution that helps extend life of building materials and home structure.
Our solution is maintenance free and 100% solar-powered with 20-year limited warranty.
Only patented retrofit solar powered attic fan on the market. Reduced risk – no new holes – fits under existing roof vents. Simple & easy to install – horizontally (rooftop) or vertically (sidewall). Can separate solar panel location from fan for optimal sun access.
Greenhouse Gas/Carbon emissions savings from direct peak-demand energy savings plus benefits to the environment from extending the life of, and reducing waste from, building materials such as shingles, insulation, and air conditioners, simply by increasing the ventilation with this 100% solar powered solution, and therefore eliminating moisture and rot and reductions in landfill from carbon-based shingles.
iSolar Product Development - Evolution
In 2022 iSolar created the next generation of its FLEXLine of its patented retrofit solar powered ventilation products. Now more durable than ever, the solar panels come with a corrosion resistant coated frame and mounting system with stainless steel gasketed screws. The power connection is a sealed electrical connection box and the wire feedthroughs are waterproof. The fan motor is built with IP68 waterproofing certification, which means it could be submerged in water and will keep running. Lastly, the fan and housing are all coated aluminum with a recycled plastic mounting plate. The patented mounting plate can be cut to fit into any opening and allows for fan installation and exchange of air flow in just minutes.
The iSolar FLEXLine currently has multiple (nine standard) airflow options to chose from which are determined by both solar panel and fan sizing. The solar panels are 20, 50, 80 or 120 watts in output power, and the corresponding fans are 6, 8 or 10 inches in diameter, offering from 300 to over 1,700 CFM of ventilation capacity depending on the configuration chosen. We can ventilate attic and crawlspace with a single system. Custom set ups available.
From the factory, the customer can also choose from a variety of passive vent combinations for a complete system, including our new integrated OPTIFlex.
Ontario system wide benefits Presented to ontario government
Benefit 3 times the cost of SPAF
| Value/Savings Source | Average Per Typical Home | Benefits Accrue To |
|---|---|---|
| Home owner bill savings (NPV 20 years, starting with current Ontario 5¢/kWh) | $1,200 | Home owner |
| Reduced impacts of mould (Assumes 1% of homes potentially affected) | $20 | Home owner |
| Extended life of roof shingles (heat damage/reduced ice damming; NPV 20 years, assuming 20% of homes in areas of larger advantage) | $65 | Home owner |
| Avoided costs to Ontario electricity system (NPV 20 years, using IESO-published assumptions) | $145 | Ontario rate payers |
| Ontario-based installation contractor revenues | $150 | Ontario business |
| Cost of Installed Units (Assumes typical 2 units per home) | -$400 | Ontario tax-payers |
| TOTAL NET BENEFITS | $1,180 | Approx. 3× the cost |
ADVANTAGES FOR ONTARIO:
- Cost-effective — more than $1,000 in net benefits per home
- Directly lowers home owner electricity bills (contributing to 12% promise)
- Reduces carbon without a tax because it maximizes impact during hot summer hours
- Creates jobs in Ontario
- Simple to install and maintenance-free with zero ongoing operation costs
- 20-year limited warranty
- Prior deployments in Ontario, supervised by the IESO, demonstrated savings and confirmed product reliability (only 0.6% of installations required attention with all issues covered by existing warranties)
Industry Partners and Supporters
