Frequently asked questions about solar

Solar modules (aka ‘panels’) capture sunlight and convert it into usable direct current (DC) through a process called the photovoltaic effect — where photons from sunlight generate an electric current within a semiconductor material which is transferred and pushed through the solar module, into the DC wiring and along to a solar inverter, which turns that direct current into usable alternating current (AC) power.

Grid tied is the common term to describe how the solar inverter is connected to utility power via your site’s existing electrical system. About 95% of all solar electric system installations in the US are grid tied. A grid tied solar inverter constantly monitors the utility grid and pushes solar power made on site to your loads. Should there be no load, power flows out through your metered electrical system on to neighboring needs. The process takes milliseconds…so fast. Your utility monitors this output in real-time, creating a payment structure (interconnection agreement) to compensate you for the power you produce. A grid tied inverter is designed to disconnect from the utility grid in the event of a power outage in order to protect line-people who may be working to restore power. Grid tied inverters that do not includes batteries are the most economical and common installation approach globally.

A hybrid inverter has both on and off grid capabilities. It typically functions as grid tied, taking power from the solar modules and converting it into usable AC power while also maintaining an ebb/flow of DC power stored in a battery bank. Hybrid inverters monitor the grid at all times. If an outage occurs, they quickly switch to powering only backup breaker loads (not the whole house!) via the batteries. If the sun is shining during extended outages, the hybrid inverter converters the solar power into high voltage DC power to replenish the batteries. Most of the hybrid inverters we use also manage an integrated generator input circuit and can tell a connected generator when to turn on/off to top off batteries during extended outages when the sun may not be present (the deep of winter). Hybrid inverters represent 1/4 of our installations across Oregon since 2018. We’ve been installing them for 20 years.

Prior to 1999, almost every solar electric system in the world was ‘off grid’, and would store solar power in a set of batteries so that it could be converted into useful power via an inverter/charger. This is often referred to as ‘off grid’. Now, most of the battery systems we install are lithium iron phosphate, paired with a hybrid solar inverter. When an outage occurs, the hybrid inverter instantly switches to power a backup loads AC electrical panel from DC power stored as chemical potential energy in the interconnected batteries. The switch happens in milliseconds, often without the lights even flickering! If there is enough sunlight out, solar power will feed in to help top off the batteries as they express their power to electrical loads. We install increments of 16 kiloWatt hour (kWh) batteries typically. We can place up to 20 kWh of batteries in a single battery enclosure. We can install, by code, 40 kWh of storage in a single indoor location (garage or utility room for residential application) and up to 120 kWh at a residential ‘site’. Different rules apply to commercial application, allowing larger battery storage options, typically pad mounted outdoors.

Every site is different because we build according to your energy use and how many solar modules will physically fit a particular situation. The industry median in Oregon right now (2026) for residential systems is $2.25 per Watt DC-$3.33 per Watt DC. The average system size is 9.5 kiloWatts, which produces between 9,000 and 12,500 kiloWatt hours per year, depending on the location. Considering the costs of supplies, labor, and permitting, complete grid-tied systems typically range from $17,000 to $26,000 before incentives, rebates and tax credits are factored in. Learn more about system cost vs. power bill savings.

Depending on your location, utility and project timing, rebates and incentives may be available to help lower the out-of-pocket cost of a solar electric system. After that, you generate a large percentage of your own electricity annually, so your power bills will go down because you need less power from the utility grid. You’ll also be insulated from future rate increases by utility companies over time, sort of like buying a block of power upfront at today’s rates, to be used for the next 25 years (the average life expectancy of a grid tied solar electric system). Grid tied solar electric systems pay for themselves with the power they create. A typical return on investment is 10-18 years now that the federal tax credit has expired for residential application. A commercial system should be a net positive investment in 7-10 years. Learn more about installation incentives and about ongoing savings from solar.

It depends on your utility provider and household income. The Energy Trust of Oregon Solar and Energy Storage Programs apply to Pacific Power and PGE customers. Other utility-specific incentives (EWEB & CLPUD for example) may be available, depending on project timing. See which incentives are currently available within your utility’s territory on our incentives page.

Yes. Energy Design Co. will include any available rebates/incentives and tax credits specific to your situation when you request a free assessment or bid from us.

Due to a high volume of interest, it generally takes 60-90 days from contract signing to system completion. Factors include: permitting, net metering/interconnection application approval, equipment availability, construction planning and inspections. A residential grid tied installation typically take three to four days for a crew of three, depending on the system size. A hybrid system with energy storage (batteries) typically takes two weeks to complete, due to the intricate AC electrical work involved. In total, each project requires a minimum of 100 hours of onsite labor hours to complete.

We are mandated to wait for your utility to come out and install(or reprogram) your new “net meter” in order for the power produced on site to be calculated properly. This can take up to two weeks for the meter shop to complete typically. Your existing meter can not differentiate if your system is pushing energy onto the grid or consuming power from the grid, so it will not calculate your power usage correctly until the net meter is installed.

Typically we bill a third of the total cost when the contract is signed. We then bill another portion when we order supplies for your project, such as solar modules, inverters and racking equipment. The final payment is due once both electrical and building inspections have passed. Since every project is unique we can often work with you to set up a payment plan that fits your financial needs.

For Energy Trust of Oregon residential projects, we do offer loans via the smart e-loan program. Due to current interest rates, Energy Design Co. is not offering financing options directly. We are happy to help you understand the lifecycle cost of a solar project and will provide detailed bid documentation suitable for securing a HELOC or other third party financing. Please let us know your questions when you request free assessment.

We were founded in 2004 by industry veteran, Vince McClellan. We have installed solar and battery systems for over 1000 sites, including many well-known Oregon businesses (happy to name drop the University of Oregon and Powell’s Books, among others). Energy Design Co. is a training agent, working with the Oregon JATC to cultivate professional solar installers through formal apprenticeship. We currently have four licensed renewable technicians (LRT) on staff and one LRT apprentice. Our lead designer, Vince McClellan, is a NABCEP certified PV professionals. Learn more about our team.

The majority of the system components we use are warranted for 10-25 years.
We service solar equipment installed in the 90’s throughout Oregon to this day. Solar modules degrade at a marginal percentage per year (typically .5% or better) when exposed to sunlight. At 25 years, they produce approximately 80 percent+ of what they did when they were new, and even then they still have a lot of life in them.
Often the solar inverter manufacturer will have a stated warranty period of 10 to 12 years with the ability to request a warranty extension to 25 years for an additional cost. We see inverters still working in the field at 25 years old.
Lithium batteries are typically warranted for 10 years or 6500-8000 cycles. Unlike lead acid batteries, we have yet to replace a lithium battery in a residential application due to depletion (2026).

We typically use equipment with a 10-25 manufacturer warranty. Energy Design Co. offers a 2-7 year workmanship warranty depending on the utility incentive program your project falls into. If anything is to go wrong with your system during our warranty period, we will fix it with no additional labor cost. After our service warranty period has ended, we do bill for labor associated with any fix necessary to get your system up and running again, should there be a problem. Visit our Solar Service Page for current rates.

About 4.1 percent, according to Zillow. A solar system has great value because it decreases your monthly power bills, gives homeowners the ability to produce their own energy, creates clean electricity, and provides the option to have batteries in case of wildfire caution, power outages, or other emergencies. By law, solar additions are property tax exempt, meaning it’s a way to increase value without paying more taxes.

These are two slightly different methods that utilities may use to allow residential and commercial customers who generate their own solar electricity to sell excess electricity back into the grid. As a solar customer, you will only be billed for your “net” energy usage and the various monthly utility fees listed on your bill. Learn more about net metering vs net billing.

Yes. If you can tell it’s daytime then there is likely enough solar irradiance to activate your inverter and produce power, even on cloudy or rainy days. However, when the days are shorter in the winter and the sun stays lower on the horizon, a solar electric system will produce considerably less power than it will at the height of summer. If panels are obstructed by snow, you’ll want to carefully remove it with a brush on an extension pole for the panels to be active. This is especially important for off-grid and hybrid battery based systems.

Very little. We do recommend an annual wipe-down with a scrub brush/squeegee. Bird droppings or debris can lower your panels’ production rate by up to 10%. We recommend dusting/vacuuming off the solar inverter, if you have a string inverter, a couple times a year as well. If we install a system for you, you’ll receive a custom Owner’s Manual, which outlines recommended maintenance.

No…unless you have an energy storage system (batteries). 95% of solar electric systems turn off during an outage in order to protect line people working in the area to restore power. Once power is restored, a grid tied inverter will turn back on and start working on it’s own.
Those who purchase hybrid inverter systems with energy storage will have power at their backup loads electric panel until the batteries are depleted. The more attention to load management during an outage, the longer a battery system will last before needing to be recharged via the sun, generator or utility power.
Many of our grid tied inverters from SMA and Fronius include a secure power supply, backup secure or PV Point enabled receptacle. This is a single switched protected receptacle that, during the first day of an outage, produces 1500-2000 Watts while the sun is out. For daytime outages, this allows you to power a refrigerator or other devices via an extension cord. No external batteries required. Ask us about this feature when requesting an assessment.

It’s not necessary, but it can be useful in the case of a power outages or emergency. If you live in an area with frequent blackouts, or if having power at all times is critical, you may want to consider an energy storage system. Energy storage systems add considerable cost and complexity to a project, but there are battery incentives to help with that too. If you think you might like to have a battery backup later but don’t need it immediately, you may be able to add batteries to your system at some later time. Let us know your situation when you get your free assessment.
It’s important to note that a grid tied solar electric system typically has a tangible payback period. As soon as you add batteries to the mix, the idea of a financial investment is replaced with resiliency. You can’t have both with the current utility rates in Oregon being so low…for now.

A building suitable for solar will have a regular composite shingle roof that is no more than eight years old with South- and/or West-facing roof areas that are unobstructed. A corrugated metal roof works well too. A standing seam metal roof is always preferred (our favorite!).
If no building on site meets this criteria, we may be able to utilize a ground-mounted solar array approach if there is a flat, clear, unobstructed site within 120′ of the existing electrical service equipment. Ground mounted systems are significantly more expensive than roof mounted. The further away the solar array site is from the electrical equipment, the more expensive the installation becomes.

It depends where they are relative to your best solar location. For projects West of the Cascade mountain range, we tend to focus on South-facing and West-facing roof areas for solar arrays. If you have trees obstructing the sun in these areas, then your building may not be a great candidate for solar. Shading can impact whether or not you meet utility incentive requirements too!

You may consider cutting the tree(s) down, but we don’t always recommend that. Depending on your energy costs and your house’s energy efficiency, the trees may actually be helping to cool your house and save you energy and money. It’s a case-by-case basis. If you want to get an idea of the shading yourself, type your address into Project Sunroof, and you can see a free shade report on your house. If you’d like more professional input, please request a free assessment from us.

It depends on how many kiloWatt hours you use per month and over the course of a year. We will look at your utility bill and available roof area to determine how many solar modules could fit and what impact they would have on your annual consumption. It’s all part of your free assessment.

Oregon requires you hire a solar/electrician professional to install the equipment for all permitted structures. Energy Design Co. has the ability to receive solar rebates and incentives on your behalf, lowering your out-of-pocket cost. Under certain situations, we can be hired to do the design documentation and deliver parts for D.I.Y. installs. Contact us with your project inquiry!

When your solar system generates energy, that energy is used up by your house appliances first. Your utility installed net meter doesn’t have the opportunity to see this demand that is being replenished directly by your generating system on site. If their is no/low demand on your side of the utility meter, solar power then feeds out through the bi-directional utility meter toward your neighbors, and is credited to your bill according to your interconnection agreement.

Net energy is the difference between the energy produced by your renewable generating system and the amount of electricity supplied by the utility. Therefore, your net meter will only show the amount of energy that was excess and passed back to the grid. Your data monitoring app, however, will show many more kilowatt hours because it is calculating the total energy being produced by your solar electric system, including the Watt/hours your house uses immediately.

For new single family construction, solar ready is a construction standard that informs the size/placement of the main electrical panel and conduit routing to the attic/roof for a future solar array to be placed.
Learn details about it here from the Energy Trust of Oregon.