Solar Proposal Red Flags: What Your Solar Company Won't Tell You

Updated March 2026 · Colorado-specific analysis

Let's be clear about what this article is and isn't. This is not an attack on the solar industry. Solar is a legitimate technology that saves real money for many Colorado homeowners. Most installers are honest businesses trying to do good work.

But the solar sales process has structural problems. High customer acquisition costs, commission-based sales teams, and complex 25-year financial projections create incentives for proposals that look better on paper than they are in practice. Understanding these dynamics doesn't make you cynical. It makes you a better buyer.

Here are the most common ways solar proposals mislead, and how to read through them.

Red Flag #1: The Phantom Federal Tax Credit

This is the most clear-cut issue we see in 2026 proposals, and it's surprisingly common.

Yet we still see proposals that include a line item for a 30% federal tax credit, reducing the apparent cost by $7,000 - $12,000. Sometimes this is an honest software error (proposal tools that haven't been updated). Sometimes it's less innocent.

What to do: Look at the "incentives" or "savings" section of your proposal. If you see "Federal ITC," "Section 25D," or "30% tax credit" applied to your cost, the bottom-line number is wrong. Ask the company to rerun the proposal without it. If they push back or claim it still exists, that tells you something about their credibility.

Red Flag #2: Inflated Utility Rate Escalation

This is the most impactful assumption in any solar proposal, and it's the hardest for most homeowners to catch.

Every proposal projects your electricity costs 25 years into the future. To do that, it assumes your utility rate will increase by a certain percentage each year. The higher that percentage, the more dramatic your "savings" look.

The math matters enormously:

Based on 10,000 kWh annual usage. Numbers rounded for clarity.

The difference between a 3% and a 6% escalation assumption is roughly $34,000 in projected savings over 25 years. That's not a rounding error. It's the difference between solar looking like a no-brainer and solar looking transformative.

Colorado reality: Xcel Energy residential rates have increased approximately 3% per year on average over the past decade. Some years more, some less. Could future increases be higher? Maybe. But projecting 5-6% annual increases as if they're a certainty is not analysis. It's marketing.

What to do: Find the escalation rate in your proposal (sometimes buried in the assumptions or appendix). If it's above 3.5%, ask the company to rerun the numbers at 3%. See how the payback period changes.

Red Flag #3: Optimistic Production Estimates

Your solar savings are directly proportional to how much electricity your system produces. Overestimate production by 15%, and your savings projection is wrong by 15%.

Production depends on your specific roof: orientation, tilt, shading from trees or neighboring structures, and local weather patterns. Good solar companies do a detailed shade analysis. Others use rough estimates that assume ideal conditions.

Colorado benchmark: A well-oriented residential system on the Front Range produces 1,450 - 1,600 kWh per installed kW per year. An 8 kW system should produce roughly 11,600 - 12,800 kWh annually. If your proposal claims 14,000+ kWh from an 8 kW system in Denver, something is off.

What to do: Run your address through NREL's PVWatts calculator with the system size and orientation from your proposal. If the proposal estimate is more than 10% above PVWatts, ask the company to explain the difference. There might be a good reason (e.g., higher-efficiency panels), but they should be able to articulate it.

Red Flag #4: Hidden Financing Costs

Solar financing has gotten creative, and not always in ways that benefit you.

Dealer fees: Most solar loans include a dealer fee that gets rolled into the loan amount. The installer receives the full system price, and you borrow the system price plus the fee. A 25% dealer fee on a $25,000 system means you're actually borrowing $31,250. Your APR might be 4.99%, but your effective cost of solar is 25% higher than the sticker price.

Dealer fees are not inherently wrong. They're how low-APR solar loans exist (the dealer fee subsidizes the rate). But they should be disclosed clearly, and you should know your total borrowing cost.

The "same as your electric bill" pitch: Many solar salespeople frame the monthly loan payment as a replacement for your electric bill. "You're paying $180/month to Xcel. Now you'll pay $175/month for solar." This framing hides several things:

• You'll still have a residual electric bill (grid connection fees, usage on cloudy days/nights). Budget $20-40/month even with solar.
• The loan payment is fixed for 15-25 years. Your electric bill would have changed.
• When the loan is paid off, your savings jump dramatically. But for the loan period, you may actually be paying more per month than you would without solar.

What to do: Ask for the total cost of the loan (principal + all interest over the full term). Compare that to the cash price. The difference is what financing costs you. Then decide if that cost is worth the convenience of not paying cash.

Red Flag #5: Outdated Net Metering Assumptions

Colorado's net metering rules changed under SB 23-258. New solar customers get credits for excess generation at a reduced rate (approximately 75% of retail), not the full retail rate that grandfathered systems receive.

Some proposals still model full retail net metering, which overstates the value of excess production. This matters most for oversized systems that export a lot of energy to the grid.

What to do: Look at how the proposal values your exported electricity. If it assumes full retail credit ($0.152/kWh on Xcel's flat rate), the savings from excess generation are overstated. The actual credit rate for new systems is closer to $0.11/kWh. For a system that exports 30% of its production, this difference can be $200-400 per year in overstated savings.

Red Flag #6: Pressure Tactics and Artificial Urgency

This one is about the sales process, not the proposal document. But it's worth flagging because it's so common.

• "This price is only good today." Solar equipment prices change slowly. A legitimate quote should be valid for at least 30 days.
• "We only have 3 installation slots left this month." Maybe. But if every sales rep says this every month, it's a script.
• "The tax credit is about to expire." It already expired. If someone says this in 2026, walk away.
• "Your neighbors already signed up." This may be true in some neighborhoods, but it's irrelevant to whether the deal is right for you.

A good solar investment works on its own merits. It doesn't require you to decide before dinner.

Red Flag #7: No Mention of Panel Degradation

Solar panels lose efficiency over time. The industry standard is approximately 0.5% per year, meaning your panels will produce about 87.5% of their original output at year 25. This is normal and expected.

A good proposal accounts for degradation in its production and savings projections. If the 25-year savings chart shows flat or increasing production year over year, the model isn't accounting for degradation.

The impact: Ignoring degradation overstates cumulative 25-year production by roughly 6-7%. Combined with inflated escalation rates and optimistic production estimates, these compounding optimisms can make a proposal look $10,000 - $20,000 better than reality.

A Note on Intent

Most of these issues aren't the result of malice. Solar is a complex product sold by commission-based teams using software with dozens of adjustable assumptions. The sales team is often trained on templates they didn't build, using escalation rates they didn't choose, promoting incentives that may have changed since the software was last updated.

That's exactly why an independent check matters. Not because your solar company is dishonest, but because the system makes it easy for proposals to drift away from accuracy, even with good intentions.