Article Summary:
- Hawaii’s 20% rule refers to HECO’s guideline that residential solar systems should not be sized to produce more than 100% of a customer’s annual electricity consumption—with important nuances around how excess generation is treated
- Oversizing a solar system in Hilo under the current Customer Self-Supply tariff results in wasted generation that earns minimal compensation, directly reducing your financial return
- The rule interacts specifically with Hilo’s climate, usage patterns, and HECO’s Big Island tariff structure in ways that mainland solar sizing guidance doesn’t account for
- Battery storage changes the calculus around sizing and can justify a modestly larger system in certain situations
- Understanding this rule before you sign a contract protects you from a common and costly system design mistake
- A solar contractor who doesn’t discuss this rule during the design process is not giving you complete guidance
- Because strict utility sizing caps and grid feed-in limits directly dictate your return on investment, understanding how much a solar system costs for a 2,000 sq ft house in Hilo, HI in 2026 helps you design an optimally scaled array that avoids wasted generation capacity.
If you’ve been researching solar in Hawaii for more than a few days, you’ve probably encountered references to rules around how large your system can or should be relative to your electricity usage. These references show up in contractor conversations, HECO documentation, and online forums where Big Island homeowners compare notes on their solar installations. And yet the specifics often feel murky—what exactly is the rule, where does it come from, and what does it mean for a Hilo homeowner trying to make a smart decision about system size?
This article answers those questions directly and in plain language.
The short version: Hawaiian Electric has guidelines around how solar systems are sized relative to your actual electricity consumption. Going significantly over your annual usage with solar production doesn’t just generate electricity you can’t use—it generates electricity that earns you very little credit under current tariff programs. In Hilo’s specific context, where HECO’s Customer Self-Supply tariff governs most new residential installations, the difference between a well-sized system and an oversized one can mean thousands of dollars of difference in financial return over the life of your installation.
Understanding this before you buy protects you from one of the most common and quietly expensive mistakes in residential solar—paying for capacity that doesn’t serve your financial interests.
Where the 20% Rule Comes From
To understand the 20% rule, you need a brief history of how Hawaii’s solar policy has evolved—because the current rules are the product of years of policy changes that reflect Hawaii’s unique grid situation.
Hawaii’s Grid Is Different
The Big Island’s electrical grid operates as an isolated island system. Unlike the continental U.S., where the grid spans interconnected regions and excess power can flow across state lines to where it’s needed, Hawai’i Island’s grid is a closed loop. Every kilowatt-hour generated has to be balanced against every kilowatt-hour consumed in real time, with no neighboring system to absorb surplus.
As rooftop solar adoption accelerated in Hawaii, this grid isolation created a genuine technical challenge. On sunny midday hours, distributed rooftop solar systems across the island collectively generated more power than the grid could easily absorb. Voltage fluctuations, frequency management issues, and potential instability became real concerns rather than theoretical ones.
HECO responded over years with a series of policy changes designed to manage solar’s impact on grid stability while still supporting customer adoption. Those changes progressively shifted the economics of solar from a model that rewarded maximum generation and export to one that rewards self-consumption—using the power you generate rather than sending it back to the grid.
The Old NEM Program and Why It’s Gone
Under Hawaii’s original Net Energy Metering (NEM) program, homeowners who exported excess solar generation to the grid received a credit at the full retail electricity rate—the same rate they paid to buy power. At over 40 cents per kWh on the Big Island, that retail-rate export credit made oversizing a solar system financially attractive. The more you generated, even if you couldn’t use it all, the more credits you accumulated.
NEM created strong economic incentives to install as much solar as your roof could hold. It also contributed to the grid management challenges described above. The program was ultimately closed to new applicants, replaced by tariff structures that changed how exported energy is valued.
Customer Self-Supply and the Shift to Self-Consumption
The Customer Self-Supply (CSS) tariff, which is the program most new residential solar customers in Hilo are placed on today, fundamentally changes the math on system sizing. Under CSS, energy your system generates while your home is consuming power—self-consumed energy—offsets your HECO bill at the full retail rate. Energy you export to the grid beyond what you’re consuming at that moment earns a credit at a much lower rate, well below the retail rate.
This export compensation structure is where the 20% rule becomes directly relevant. If your system generates significantly more energy than you consume over the course of a year, the excess generation that goes to the grid earns you very little compared to what it would have earned under NEM. You paid for that extra capacity, and it’s not delivering the financial return you might have expected.
HECO’s Sizing Guideline
HECO’s interconnection rules and associated tariff program guidance establish that residential solar systems should generally not be sized to produce more than 100% of a customer’s annual electricity consumption. The practical implementation of this guideline—sometimes referenced as the basis for what contractors call the 20% rule—means that contractors should be designing systems to offset your usage, not to exceed it by a meaningful margin.
The “20% rule” as it’s commonly discussed in Hawaii solar circles typically refers to one of two related concepts:
The interconnection sizing constraint: HECO’s technical review of interconnection applications looks at whether a proposed system’s output is reasonably matched to the applicant’s historical consumption. Systems designed to generate significantly more than the customer’s annual usage may face additional scrutiny or may be required to reduce system size to receive interconnection approval.
The financial self-consumption principle: A well-designed system under CSS should target generating approximately 80-100% of your annual consumption from solar—leaving a small amount of grid consumption rather than exporting significant excess—because the 20% or more of generation that would go to the grid as excess export earns minimal compensation. The rule of thumb that circulates among informed Hilo homeowners is essentially: don’t size your system to produce more than what you’ll actually consume, because the excess earns you almost nothing.
Both concepts lead to the same practical conclusion for system design: your solar system should be sized around your actual electricity usage, not around maximizing panel count or generating impressive gross production numbers.
Why This Matters More in Hilo Than Most Places
Hawaii’s CSS tariff applies across HECO’s service territories, but the 20% rule has particular practical significance in Hilo for reasons specific to the east side of the Big Island.
Hilo’s Variable Solar Resource
Hilo’s weather is hyperlocal and variable. Some neighborhoods get consistent morning sun with afternoon cloud cover rolling in from the ocean. Others sit under more persistent cloud cover due to terrain interaction with trade winds. Vog from Kilauea periodically reduces irradiance across lower Hilo and Puna. And then there are the genuinely gorgeous stretches of weather where the system produces significantly more than average.
This variability means that production estimates for Hilo systems involve more uncertainty than estimates for drier, more consistent climates. A system that’s designed to produce exactly 100% of your annual usage on average may produce 80% in a particularly rainy stretch and 120% during a sunny period.
The implication for system sizing: building in a small buffer—perhaps sizing for 90-95% of annual consumption rather than exactly 100%—makes sense in Hilo because weather variability means you’ll sometimes fall short of your target offset. But building in a large buffer by oversizing the system doesn’t improve your financial situation under CSS—it just means more excess generation earning minimal grid export credit.
HECO Rates and Self-Consumption Value
At over 40 cents per kWh for many Big Island residential customers, every kilowatt-hour of self-consumed solar generation is worth more on the Big Island than almost anywhere else in the country. This high retail rate makes self-consumed solar extremely valuable—and makes excess export, credited at well below retail rates, a particularly poor use of generation capacity by comparison.
In a market where retail electricity costs 12 cents per kWh, the difference between self-consuming and exporting is less dramatic. In Hilo, where retail rates are 3-4 times higher, the difference is enormous. A kilowatt-hour your panels generate while your home is consuming it saves you 40+ cents. A kilowatt-hour that goes to the grid earns you a small fraction of that.
This amplified contrast between self-consumption value and export value makes the system sizing decision more financially significant in Hilo than in most mainland markets. Getting the size right—designed for your actual consumption, under your specific tariff, for Hilo’s specific solar resource—has a larger impact on lifetime financial return than it would in a market with lower electricity costs.
The Addition of Electric Vehicles and Other Future Loads
One complexity specific to Hilo homeowners thinking about system sizing involves future electricity loads that don’t yet exist. Electric vehicle adoption is growing significantly on the Big Island. Homeowners who are considering an EV in the next few years may wonder whether they should size their solar system for their current usage or anticipate the additional charging load.
This is a legitimate design consideration, and it creates a nuanced conversation around the 20% rule. If you’re planning to add a vehicle that will add 300-400 kWh per month to your electricity consumption, sizing your system for that future load rather than your current usage isn’t oversizing—it’s appropriately planning for consumption you’ll actually have.
The key distinction is between sizing for actual anticipated consumption versus sizing with the hope that excess generation earns meaningful export credit. The former is good design planning. The latter misunderstands how CSS compensates excess generation.
A qualified solar contractor in Hilo should have this conversation with you explicitly during the design process—asking about upcoming loads like EVs, pool additions, air conditioning in currently uncooled rooms, or other changes that could meaningfully affect your future consumption.
How the 20% Rule Affects System Design in Practice
Understanding the rule conceptually is useful. Understanding what it means for the actual proposal you’re evaluating is more immediately practical.
What a Properly Sized System Looks Like
A solar system properly sized for a Hilo homeowner under the 20% rule framework starts with a careful analysis of 12 months of actual HECO bill history. From that history, your contractor determines:
Annual kWh consumption: The total electricity you consumed over 12 months. This is the target the system is designed to offset.
Monthly consumption patterns: How your usage varies across the year. Some Hilo households use significantly more electricity in summer months if AC use is seasonal. Others have relatively flat usage year-round. Understanding the shape of your consumption helps with production matching.
Peak consumption periods: When during the day and year you use the most electricity. Under CSS, a system that generates power primarily when you’re consuming it is more valuable than one that generates when you’re not home.
With this consumption data and a thorough shading and production analysis for your specific roof, your contractor models the system size that produces approximately 90-100% of your annual consumption under Hilo’s solar resource conditions.
For most 2,000 square foot Hilo homes, this process results in a system recommendation somewhere between 7 kW and 12 kW as discussed in our companion article on solar costs. The specific size within that range is determined by your actual bills—not by a rule of thumb based on square footage, not by what fits on your roof, and not by what produces the most impressive-looking annual generation number.
Red Flags in a Proposal That Ignores This Rule
Certain patterns in a solar proposal suggest a contractor who isn’t applying the 20% rule appropriately in their system design.
A system producing significantly more than your current annual consumption. If your proposal shows estimated annual production of 18,000 kWh against documented annual consumption of 12,000 kWh, ask directly why the system is sized to produce 50% more than you use. The answer should either explain anticipated future loads that justify the additional capacity, or it should prompt a redesign.
No reference to your HECO tariff program in the proposal. A contractor who doesn’t discuss your tariff in the context of system sizing hasn’t connected the two pieces of information that matter most for your design. Your tariff determines what excess generation is worth—and a contractor designing your system without that context may be sizing it for a different tariff’s economics than the one you’ll actually be placed on.
Production estimates showing large monthly export credits. Under CSS, large monthly export credits are a signal that your system is generating significantly more than you’re consuming. They look attractive in a financial model—they’re money coming back to you—but they represent generation valued at a fraction of what self-consumed generation saves you. A proposal built around large export credits is making your system’s economics look better than they actually are under CSS.
Maximizing roof coverage regardless of consumption. Some contractors default to filling your roof with as many panels as will fit and then describing that as a system “designed for your home.” Filling your roof with panels and sizing your system for your consumption are not the same thing. If your roof can fit 25 panels but your consumption only justifies 18, the appropriate system uses 18 panels—not 25.
When a Larger System Makes Sense Despite the Rule
The 20% rule is a guideline grounded in the economics of the CSS tariff, not an absolute prohibition. There are legitimate situations where a Hilo homeowner might reasonably choose a system sized to produce somewhat more than current annual consumption:
Planned EV adoption. If you’re buying an electric vehicle in the next 12-18 months, sizing your system for the expected charging load is appropriate forward planning. An EV charging primarily at home on solar adds 200-500 kWh of monthly demand depending on how much you drive. A system sized for that future consumption is sized for your actual anticipated needs, not oversized.
Planned additions of other electrical loads. Adding air conditioning to rooms currently without it, installing a pool or hot tub, converting from propane appliances to electric—any of these meaningfully increases your future consumption. Sizing for anticipated rather than current consumption is defensible when the additional loads are concrete and near-term.
Battery storage systems. Adding a battery storage system to your solar installation changes the sizing conversation. With battery storage, the system can generate more than you’re consuming during peak solar hours, store the excess in the battery, and then dispatch that stored energy during evening hours when panels aren’t producing. This self-consumption-through-storage model means a modestly larger system can still achieve high self-consumption rates rather than sending excess to the grid for low export credit.
Replacement of energy-intensive appliances. If you’re planning to replace a gas water heater with a heat pump water heater, or replace an old inefficient AC system with a new heat pump system that runs more efficiently, your consumption picture changes. A knowledgeable contractor accounts for planned efficiency improvements and appliance changes when modeling your future consumption.
In each of these cases, the rationale for a larger system is grounded in real, anticipated consumption—not in a hope that excess generation earns meaningful export revenue.
Battery Storage and the 20% Rule: A Different Calculation
Battery storage has become an increasingly significant part of solar installations in Hilo, and it changes the system sizing analysis in meaningful ways worth understanding separately.
How Batteries Shift the Self-Consumption Math
Without battery storage, your solar system generates power in real time. When the sun is up and your home is consuming power, solar offsets your grid draw directly. When your panels are generating more than you’re consuming—during peak midday hours when the sun is strong and your AC, refrigerator, and other loads are running but not at maximum demand—excess generation goes to the grid for minimal CSS export credit.
With battery storage, that midday excess generation can be captured and stored. Instead of going to the grid at low export rates, it charges your battery. In the evening when panels stop producing and your home continues drawing power, the battery discharges to supply your demand—replacing grid power you would otherwise be purchasing at retail rates.
This shift means that a system paired with battery storage can achieve higher effective self-consumption rates than a system without storage. Power that would have been exported at low CSS rates under a panel-only system becomes stored energy dispatched at peak evening hours, offsetting grid power at retail rates.
The financial implication is that battery storage can justify modestly larger system sizing. If a battery can capture an additional 10-15% of generation that would otherwise export at low rates and instead convert it to peak-hour self-consumption, the effective return on that additional generation improves significantly.
Time-of-Use Rates and Battery Dispatch
HECO has implemented time-of-use rate structures for some Big Island customers, creating peak and off-peak pricing periods where electricity costs more during evening hours when solar is no longer producing. For homeowners on a time-of-use rate, a battery system dispatching stored solar energy during peak-price evening hours is saving money at the highest possible per-kWh value.
This interaction between battery storage, time-of-use rates, and solar system sizing is exactly the kind of nuanced design conversation a qualified local solar contractor should be having with you. The right combination of system size and battery capacity depends on your specific rate structure, your consumption timing patterns, and your goals around energy independence versus pure financial optimization.
Critical Loads Backup and System Sizing
Some Hilo homeowners are motivated by grid reliability considerations as much as financial ones. Power outages on the Big Island—whether from weather events, grid maintenance, or unexpected equipment failures on an isolated island grid—are a practical reality. A battery system that provides backup power for critical loads during outages has value beyond its financial contribution to daily energy savings.
For homeowners prioritizing backup capability, system sizing may be driven partly by how much power they need during an outage rather than purely by annual consumption offset. A system sized to power critical loads through an extended outage period—refrigerator, water pump, essential lighting, medical equipment, communications—may be modestly larger than pure consumption-offset math would suggest.
This is another legitimate reason a Hilo homeowner might choose a system that produces somewhat above current annual consumption, provided they’re clear-eyed about the fact that the additional capacity is serving backup and reliability goals rather than financial optimization goals.
What to Ask Your Solar Contractor About System Sizing
Armed with an understanding of the 20% rule and its implications for Hilo, here are the specific questions to raise with any contractor you’re evaluating.
During the Initial Consultation
What HECO tariff program will my system be placed on, and how does that tariff handle excess generation?
This question should come early. If the contractor can’t answer it clearly—or pivots to discussing incentives without actually addressing tariff compensation for excess export—that’s a gap in their knowledge that will affect system design quality.
How will you use my actual HECO bill history to size my system?
A legitimate answer describes reviewing 12 months of bills to determine annual consumption, understanding monthly usage patterns, and designing the system to offset a specific percentage of that consumption under Hilo’s solar resource conditions. An answer that doesn’t reference your bills suggests a sizing approach based on generic assumptions rather than your actual energy situation.
Does this proposal account for any planned changes to my electricity consumption?
This opens the conversation about EVs, appliance changes, addition of AC, or other load changes that should inform system sizing decisions.
When Reviewing the Proposal
What percentage of my annual electricity consumption does this system’s production estimate represent?
Do the math from the numbers in the proposal. If estimated annual production is significantly above your annual consumption, ask for the rationale.
Under the CSS tariff, what does this proposal project I’ll export to the grid annually, and at what rate is that export compensated?
A well-designed proposal should show modest export levels under CSS—evidence that the system is sized primarily for self-consumption. Large projected export volumes, credited at well below retail rates, are a design flag.
If I add an EV or other significant electrical load in the next few years, how would that affect the recommendation?
A contractor who has thought about your long-term energy situation will have an answer to this. One who hasn’t will need to think about it on the spot—which tells you something about how thoroughly they’ve approached your situation.
Has this system size been validated against HECO’s interconnection sizing guidelines for my consumption level?
This question confirms the contractor is aware of HECO’s interconnection standards and has designed the system to pass review without requiring resizing after submission. Systems that are significantly oversized relative to consumption can be flagged during HECO’s interconnection review process—a delay that can be avoided with proper upfront design.
Common Misconceptions About the 20% Rule
Several misunderstandings about this rule circulate among Hilo homeowners and are worth addressing directly.
“Bigger Is Always Better for Solar”
This belief made more sense under the old NEM program, where excess generation earned retail-rate credits and larger systems consistently produced higher financial returns. Under CSS, bigger is better only up to the point where additional generation is actually consumed—either directly or through battery storage. Beyond that point, additional capacity generates excess export at low rates, and the financial case for that extra capacity weakens considerably.
“I Should Maximize My Roof Space”
Your roof’s capacity to hold panels and your home’s ability to beneficially use the power those panels generate are two different things. Filling your roof to maximum panel count is a reasonable goal only if your consumption justifies the full system output. If it doesn’t, the additional panels generate revenue at CSS export rates rather than at retail-rate self-consumption value—and you paid installation cost for that extra capacity.
“The 20% Rule Means I Can’t Install a System That Produces More Than 80% of My Usage”
This is a common misreading. The 20% rule is not a ceiling on self-consumption—it’s a caution against significant oversizing. A well-designed system under CSS typically targets 90-100% offset of annual consumption, not 80%. The rule is about avoiding significant production beyond your consumption, not about limiting the value you can get from solar.
“If I Plan to Add an EV Someday, I Should Definitely Oversize Now”
“Someday” is too vague a timeframe to drive current system sizing decisions. If an EV is a concrete plan within 12-18 months, that’s reasonable to factor into sizing. If it’s a vague future possibility with no specific timeline, sizing your current system around hypothetical future consumption that may or may not materialize is genuinely oversizing—and you’ll spend years paying for capacity that earns minimal CSS export credit while you’re not yet charging a vehicle.
“A Larger System Is Better for Resale Value”
The relationship between solar system size and home resale value in Hilo is more nuanced than “bigger is worth more.” An appropriately sized system that has been performing well and generating meaningful utility bill savings has clear, demonstrable value to a buyer. A significantly oversized system may actually raise questions from a buyer’s agent or appraiser about why the system is producing so much more than the home uses.
How the 20% Rule Affects Your Financial Return Over Time
To make this concrete, consider how system sizing relative to consumption actually plays out in the financial picture over a 25-year system life.
Well-Sized System Scenario
A Hilo household consuming 11,000 kWh per year installs a system sized to produce approximately 10,500 kWh annually—about 95% of their annual consumption. Under CSS:
- Approximately 85-90% of production is self-consumed directly or through battery storage
- 10-15% is exported to the grid at low CSS export rates
- Annual self-consumption savings at $0.42/kWh: approximately $3,750-$3,960
- Annual export credit at, say, $0.10/kWh: approximately $105-$157
- Total annual financial benefit: approximately $3,855-$4,117
Oversized System Scenario
The same household installs a system sized to produce 14,000 kWh annually—about 127% of their annual consumption. The additional 3,500 kWh of annual production goes predominantly to grid export under CSS:
- Self-consumed portion remains similar to the well-sized scenario: approximately $3,750-$3,960
- Additional 3,500 kWh exported at $0.10/kWh: approximately $350
- Total annual financial benefit: approximately $4,100-$4,310
The oversized system produces only about $250-$350 more per year in total financial benefit—while costing meaningfully more to install. Additional panels, additional racking hardware, more labor—the incremental cost of that extra capacity is real, while the additional financial return is modest at CSS export rates.
Over 25 years, the oversized system might generate $6,000-$8,000 more in total financial benefit compared to the well-sized system—while having cost $4,000-$8,000 more to install. The financial case for oversizing under CSS is, at best, break-even over the system life—and that’s before accounting for the time value of money and the higher upfront cost.
This comparison isn’t an argument against solar. It’s an argument for smart sizing. The well-sized system in this example still provides an excellent financial return—just without the drag of paying for capacity that earns low export compensation rather than high self-consumption value.
Changes to Watch: Hawaii Solar Policy Is Not Static
The 20% rule and the tariff structure behind it reflect Hawaii’s solar policy at a specific point in time. That policy has changed repeatedly over the years and will likely continue to evolve.
Why Policy Changes Matter for System Sizing
Decisions made about system sizing today are locked in for the next 25 years of system life. The tariff program you’re placed on at interconnection typically governs your system’s compensation structure for a meaningful grandfathering period, but broader policy shifts can affect the economics of solar ownership over a long timeframe.
Hilo homeowners who installed under the original NEM program are grandfathered into retail-rate export credits that no longer exist for new customers. Homeowners who install today under CSS are locked into that program’s structure for their grandfathering period. How solar policy continues to evolve after that period is genuinely uncertain.
What a Good Contractor Should Tell You About Policy Risk
An honest solar contractor in Hilo should acknowledge that Hawaii’s solar policy landscape has changed in the past and may change again. They should size your system to maximize financial return under current tariff rules—which means the CSS self-consumption approach described in this article—while being transparent that future policy changes could affect the long-term picture.
What they should not do is design your system for tariff structures that no longer exist for new customers, or promise that current export compensation rates will persist for 25 years without acknowledging the policy uncertainty inherent in that assumption.
Putting the 20% Rule Into Your Decision-Making
Understanding the 20% rule changes how you evaluate solar proposals in a few concrete ways.
When you receive a proposal, calculate the ratio of estimated annual production to your documented annual consumption. A well-designed proposal targeting 90-100% offset looks very different from one targeting 130% or more. The difference in that ratio is a signal about how carefully the contractor has designed the system for your specific situation and tariff.
When a contractor recommends a system size, ask them to walk you through the production estimate and explain how it relates to your consumption and your CSS tariff. The explanation should be specific—grounded in your actual bills and your site’s specific solar resource—rather than generic talking points about solar savings.
When comparing proposals, pay attention to whether production estimates are similarly calibrated across contractors. A contractor whose production estimate for the same site is 30% higher than the other two you received is likely using optimistic assumptions—higher peak sun hours, lower system loss factors, less shading adjustment. Those optimistic assumptions inflate both the system’s apparent financial return and, often, the implied argument for a larger system.
The goal of all of this isn’t to talk yourself out of solar or into a minimal system. It’s to get a system sized for your actual consumption, designed for your actual tariff, that delivers the financial return you’re counting on rather than a financial return that looked good on a proposal but underperforms in practice.
A Note on Working With Contractors Who Truly Know HECO
The 20% rule isn’t something a homeowner should have to explain to their solar contractor. It should be something the contractor explains to you—proactively, early in the design conversation, as a fundamental parameter that shapes their system recommendation.
When you’re evaluating contractors for a Hilo solar installation, how they handle the system sizing conversation is one of the clearest windows into their competence and their alignment with your interests. A contractor who maximizes system size without discussing CSS tariff economics may be doing so because they earn more on a larger installation—or because they genuinely don’t understand how HECO’s current tariff structure affects the value of excess generation. Neither is a good reason to trust them with your system design.
A contractor who explains the 20% rule, walks you through how your CSS tariff affects sizing decisions, and designs a system specifically calibrated to your documented consumption and your Hilo-specific solar resource is demonstrating exactly the kind of knowledge and client alignment you’re looking for.
The 20% Rule and Your Long-Term Satisfaction With Solar
Most of the homeowners who end up disappointed with their solar investment in Hawaii share a common story: their system was oversized relative to their consumption under a tariff that rewards self-consumption, their contractor didn’t explain this clearly, and their financial return has consistently fallen short of what the proposal projected.
The proposal looked good. The system size felt impressive. The production numbers were high. But the actual bill savings didn’t match the projections because significant portions of generation are earning export credit rather than displacing retail-rate consumption—and that gap between projected and actual performance compounds year after year.
Understanding the 20% rule before you buy is the way to avoid that story. It takes a bit more upfront education than most solar marketing asks you to absorb, but it pays off in a system that performs the way you expected it to, delivers the financial return you were counting on, and leaves you feeling like you made a genuinely informed decision.
That’s what good solar looks like in Hilo. Not the biggest system on the block—the right system for your home, your consumption, your tariff, and your goals.
Solar Saint Gets the Sizing Right From the Start
At Solar Saint, every system we design for a Hilo homeowner starts with your actual HECO bills and a clear conversation about your CSS tariff. We explain the 20% rule before we propose a system size, not after. We design for self-consumption optimization, and when battery storage or planned load additions change the sizing calculus, we walk you through exactly why.
We’re not going to propose the largest system your roof can hold and let you figure out later that the financial return doesn’t match what the numbers implied. We’re going to propose the right system for your home—one that performs the way you expect for the next 25 years.
Visit Solar Saint to schedule your free consultation and site assessment. Bring your last 12 months of HECO bills, and we’ll show you exactly what a properly sized Hilo solar system looks like for your specific home and energy situation.
