Home Solar 101: Grid-Tied vs. Off-Grid Solar Systems

Whether you are committed to adding solar to your home or just beginning to explore the idea, perhaps the earliest and most important choice to make in designing a solar power system is whether your system is grid-tied or off-grid.

Grid-tied solar power systems mean that your home is still connected to the local power grid. If your home’s electricity needs are beyond the production of your solar panels, then the power grid covers the difference. An off-grid solar power system is just that. There is no tie-in to the utility lines, so all of the power for your home must come from your panels, energy they’ve stored in batteries, or additional power generators.

There is also a middle ground between grid-tied and off-grid. This third option, called a hybrid system, has an energy storage component, like most off-grid systems, but maintains a connection to the power grid.

So, which is right for you?

Grid-tied systems are the least expensive and most popular option for homeowners who live in close proximity to the power grid. Off-grid systems have the added cost of batteries and/or gas generators, so these systems are most popular for remote locations where the cost of extending power lines becomes a key factor. Hybrid systems fall between these two in terms of cost and offer the most flexibility for homeowners wanting to get good returns on energy sent back to the grid.

That is the simple breakdown. Beyond cost and location, the choice to keep a grid connection or sever the grid cord depends on your own energy and environmental goals as well as some site-specific parameters. Below are in-depth explanations of each system set up to guide your choice.

Grid tied solar

 

GRID-TIED SOLAR SYSTEMS

The simplest of the three options, a grid-tied system, is the most popular choice for a reason. Grid-tied systems have the lowest upfront costs and are the easiest to integrate into your current way of living (electricity pun definitely intended).

Your local utility provides power whenever the solar panels cannot cover the energy load themselves, for instance at night or on cloudy days, so there is no requirement to also add batteries or a backup generator. Grid-tied systems can also be more flexible in terms of sizing. Homeowners can let their budget guide how many panels to install and not worry about meeting the entire home’s energy demand.

This flexibility is another reason grid-tied systems are usually cheaper. They can also be designed to allow for additional panels to be added in the future, for example, if you’re anticipating a new electric vehicle in your future.

When the solar panels produce more energy than your home requires, often during the radiant afternoon sun, that extra energy can be sent back to the grid in exchange for electricity credits. These credits can then be used during periods when the panels are not producing.. This process is called net-metering, which is a key factor for grid-tied systems’ return on investment. Net-metering structures differ by utility and state, so it is important to check on your local electricity provider’s net-metering policy. Generally, the power your grid-tied system sends back to the grid is credited towards a deduction off of your monthly electric bill.

The cost-effectiveness of grid-tied solar systems does rely on close proximity to the power grid. Extending transmission lines can get expensive, so off-grid solar systems are more typical for remote properties. Generally, if your home or business is more than 100 yards from the power grid, then off-grid options may be worth exploring.

Another consideration for grid-tied systems is that they will not provide power during an outage without additional equipment like an energy storage device, even if the sun is shining. This is to protect the utility workers who need the lines to be dead to safely complete their repairs. Shutting off grid-tied solar power systems during outages ensures there is no surprise solar electricity sent back through lines when they are being repaired.

Montana Cabin with Off-Grid Solar System

OFF-GRID SOLAR SYSTEMS

For those looking for complete independence from their power company, or with a home or business in a remote location, off-grid solar systems are the place to start. These systems are more complex and expensive than their grid-tied counterparts because it is highly recommended to include a battery storage system, backup generator, or both.

These are needed because there is no grid connection to provide power when the sun isn’t shining. A solar battery bank stores excess energy during the day and supplies power as needed, during the night or other high-demand periods.

Off-grid solar installations do add thousands to upfront investment costs as additional equipment is required to successfully power your home 24/7. However, if your home is far enough from the power grid, then the investment in solar battery storage can be cheaper than the cost to extend the electric lines, particularly if it means crossing difficult terrain. There are also specific situations, such as outlying buildings on a large property, that are best suited for off-grid solar while the main compound remains grid-tied.

Even if you live next to the grid, some energy-conscious clients prefer to generate all of their own power, local regulations permitting. Installing an off-grid solar power system also means never receiving another bill from the electric utility.

Off-grid clients also separate themselves from the environmental footprint of the local power company and the energy inefficiencies associated with distribution. Not worrying about raising electric rates or changing utility policies, especially potentially volatile net-metering changes, has some serious appeal.

As mentioned, the off-grid solar system will be pricier, as batteries and other associated components will be needed. The sizing requirements of the solar power system also become more rigid. The panel array needs to be large enough to meet the demands of your building, or additional generators should be considered. For this reason, off-grid systems work best for low electricity demand homes, like net-zero homes, or those willing to invest in energy efficiency retrofits.

Even when properly sized, off-grid solar clients should be prepared to handle brief periods without power. There can always be unexpected circumstances that drain through battery backups, and you have to wait for the sunshine to return to recharge. This restrictive lifestyle is also why investing in a backup gas generator is a popular addition to off-grid systems.

Hybrid solar system

HYBRID SOLAR SYSTEMS

When you combine elements of both grid-tied and off-grid systems, you get the hybrid option, also called grid-tied plus storage or solar+storage. Hybrid solar power systems include any that feature a storage component but are not meant to be entirely off-grid.

Hybrid systems are on the rise as solar battery technology continues to improve in efficiency and drop in price. Furthermore, innovative local incentives and programs have started popping up across the nation to encourage the addition of battery backups for added energy resiliency. The upfront cost of a hybrid system is cheaper than a fully off-grid system but more expensive than the remaining grid-tied, so be sure to check with your installer for local rebates and other incentives.

Some hybrid systems use batteries purely in a backup capacity to provide power during outages. Other hybrid systems use battery storage to avoid purchasing electricity when it’s most expensive, called time-of-use rates. As “smart solar” technologies improve and utilities continue to adopt time-weighted rate structures, hybrid solar power systems are in the best position to maximize net-metering savings.

The additional battery storage costs mean that hybrid systems will not be cheaper than most grid-tied options. However, since the battery bank doesn’t have to be sized to meet all of the power needs of your home, it can be smaller, making the upfront investment more manageable than a fully off-grid system.

Be it grid-tied, off-grid, or hybrid, all system designs will give you significant solar benefits, like lowering your energy bill and diminishing your environmental footprint. Our IPS system professional will use your budget and energy goals to design the solar power system that is just right for you.

To request a free quote, contact Independent Power today.

High Altitude Rocky Mountain off-Grid Solar

Richard Marchese contacted Independent Power seeking an off-the-grid power system for his home which sits above the tiny town of Ward, Colorado at 9,500 feet on a south-facing slope with a view of Colorado’s front range.

A long-time on-and-off Boulderite, a self-professed sixties hippie of New Jersey origins, Richard is finally retiring to his longstanding dream cabin which he built decades ago.

The electrical load requirements for Richard’s cabin were relatively typical (the one exception being his steam shower which pulls 8000 Watts).

Richard is now served by a robust IPS off-grid power system that boasts our top-quality equipment and engineering: SunPower panels on our custom ‘floating’ ground mount array, Concorde AGM batteries, Outback Power inverter and charge controllers, and both a propane Kohler DC generator and a backup gasoline Honda AC generator. Working together they provide a super-efficient, reliable, and seamless supply of power to his home including his steam shower – just like he has always wanted!

1.  Why did you decide to choose to go with an off-grid power system rather than extending the grid?
In brief, I wanted independence.

2.  What were your concerns – if any – about going with an off-grid system?
It was important to find the right company to accomplish this. I interviewed three solar companies. It was pretty obvious to me that IPS was the one on the ball. Tony, the owner of Independent Power looked around my property, picked out the perfect place for the batteries, then drew me a sketch as he explained how the system would work. His system would employ a special DC generator that has served duty in many remote locations. (DC generators are typically used for remote telecommunication sites. Rarely are they used for off-grid home systems but are attractive as they are much more fuel-efficient than AC generators.)It is a very quiet generator. The solar modules are mounted on high-grade steel and are welded together to stand up against the very high winds common at this altitude. The inverter, charge controllers, power monitor, and solar panels are the latest proven technologies available.

The experience of going solar in New Jersey, my former home, had me pretty disenchanted. The state, unfortunately, has not been very supportive of distributed energy solar, which is solar panels on residences.

3.  How long have you had your system, and are you glad you made the decision to do it?
I have had my system for several months now. And yes, I’m very happy I went off-grid and that I found IPS to do the installation. It is not yet complete. Winter – and the accompanying snow –  set in. The finishing touches will be installed this summer.

4. Has your system worked as you expected?
Absolutely. It takes care of itself. It’s designed to do that, but IPS advised me to keep tabs on the generator. It is electro-mechanical and needs to be monitored until you are satisfied that all is functioning as designed. An Internet connection—that IPS recommended—will be installed next and will enable IPS and me to monitor the vitals from Boulder or anywhere the Internet exists.

Panels in the snow

5. Do you have any regrets about not extending the power line?
No.

6.  Do you have any advice for someone considering an off-grid system?
If you are an old-timer, have money. I am retired and will not get any help from the 30% federal tax credit. This credit should have been a “refundable” credit; then old folks and retired vets like me would get the same break as folks who are still working and earning enough to pay taxes. It would have been worth about $15,000. I had to borrow an additional $12,000 from the bank to finish off the system as envisioned (I could have made it smaller to compensate) because the 30% federal tax credit is not refundable. Check with your accountant to make sure you can get, and use, the 30% federal tax credit. Living on my Social Security the last thing I needed was another monthly payment to the bank.

7.  Are you happy with IPS’ performance in working with you and delivering as you expected?
The Boulder permit hurdles made it tough for IPS to put the system where it would do the most good. IPS went to bat for me. They handled the phone calls, meetings with inspectors, a town hearing and were able to have the permits issued for the optimum placement of those sixteen 327 watt panels (which were ground-mounted just east of my house, directly in the sun).  I could have never accomplished this. These delays put IPS into the early winter up here at 9000 ft. This had a snowball effect – literally – of more delays due to the mountain weather, wind-fallen trees in the way, snow drifted roads blocking the access. IPS workers came with a chain saw to clear the road and get some more work done.

When the weather made it impossible to get a wet cement truck in, IPS used wheelbarrows and a pickup truck to ferry batches of cement bags to the three 2’x5′ cylindrical forms that would hold the poles for theframe that the panels would be mounted on. A lesser company may have thrown their hands up and said “See you next spring.” The folks at IPS made sure I didn’t go through another winter using a generator.

8.  What was your motivation for building a house with an off-grid system? And how is the experience living in your off-grid home?
I wanted a self-contained house. A sort of Space Station on the earth, capable of supporting life in the harshest environment of winters up here.

SYSTEM OVERVIEW

  • 5.232 kW SunPower PV Array
  • 16 SPR-E327 SunPower panels
  • 45 kWh of battery storage  – AGM, sealed, maintenance-free
  • Inverter – Radian 8000 watt
  • Kohler generator (primary) with Honda backup
  • Azimuth 165
  • Tilt 45 degrees, installed on IPS custom ground mount
  • Estimated pounds of greenhouse gases saved: 6 tons/year
  • The solar system produces on average 15 – 30 kWh / day depending on the season

Want a state-of-the-art off-grid power system for your home? Click here to contact Independent Power today.

Living off the Grid: The Tiny House Revolution

The tiny house movement, also known as the small house movement, is a popular tag for the social and house building movement that vouches for simple living in small, off-the-grid homes. The small house movement is made up of an exponentially growing movement of tiny house enthusiasts who are concerned about the environment and sustainability. They are not so concerned with a square footage of a home in order to feel like they are living some type of successful life; in fact, they think small is beautiful.

You might think that tiny house living would be almost impossible, but actually, options for tiny house users are increasing. As a matter of fact, tiny house villages are now being tried as a solution to combat homelessness. Within this movement are a group of users who are taking the simplicity, freedom, and sustainability of tiny houses to a whole new level by constructing their houses completely off the power grid. These people are known to use renewable forms of energy such as solar energy, wind power, and micro-hydropower to run their homes.

Living in a tiny house, off the grid, is an excellent way of reducing your ecological footprint and saving a lot of money while you are at it. One advantage of living in a tiny house is that you free up a lot of energy, money, and time. Such resources would otherwise be used in paying rent, mortgage or in running a house. There is no consensus on the cost of setting up a tiny house, as it depends on several variables. These include the amount of money you spend on the off-grid energy source you opt for, the option you choose for heating the house, whether you construct the house yourself or professionally, and whether you choose simplicity or luxury.

The cost of building a tiny house can run anywhere from $8,000 to upwards of $50,000 depending on the materials used and the size.  For those who have a tighter budget, recycled materials may be used and the labor may be done by themselves.  A pre-made solar unit may cost approximately $5,000. However, if you choose to build your solar unit yourself, a pair of solar panels, batteries, a charge controller, and an inverter should cost around $3500 to $4,000 depending on their quality, efficiency, and place of purchase.

SOLAR PANELS FOR TINY HOUSES

Solar panels are a popular option for energy in a tiny house. The solar energy unit is an investment with no recurring costs. In fact, solar panels are known to have a lifespan of over 25 years (many exceeding 40 years). The batteries may need to be replaced every 5 to 10 years though, depending on your use.

Costs of Solar For Tiny Houses

Living in an off-the-grid tiny house ensures that you pay no monthly electricity and water bills. Some minor costs may come up here and there, however, paying no energy bills goes a long way in offsetting these costs. If you work at home, you may incur some phone and internet bills, you may also have to purchase alternative fuel like propane or butane.

OTHER CONSIDERATIONS

If you opt to be a minimalist tiny house owner, you can live without electricity, phones, internet, or propane. This means that you will use wood stoves and lanterns. Wind is a good alternative for solar energy, but buying wind turbines can be an expensive affair. In addition to this, they only work when sufficient wind blows. If you choose a location near a river or a stream, you can look into using micro-hydro power to provide your energy requirements.

It is important to find a water source before you decide to purchase the land for building your tiny house. Most localities require the use of an approved source of water. These include a cistern tank with a delivery system or a professionally drilled well. Drilling a well is expensive, so a cistern would, therefore, make great economic sense. If you use rainwater to fulfill some of your water requirements, it has to be filtered and treated to guarantee its safety. A standard water filter should set you back by about $300.

Tiny house living is already changing the world and is expected to continue to increase. In 2006, about 100,000 American houses were tiny, off-the-grid houses. Off the grid tiny house living is not about competing with other people, as it is about opting to live a lifestyle that you believe is comfortable and suits you. With the economic crisis and Mother Nature taking a toll due to all of the energy pull from mass consumerism and the abuse of natural resources, the tiny house movement ought to be welcomed with open arms. Unfortunately, there are plenty of people against the movement because when people downsize, the economy can feel the effects over the long haul.

If you’re interested in the tiny house movement and off-grid solar energy living, continue to research the tiny house movement.  Some cities have workshops that help men and women learn how to build their own tiny houses.  Simplicity is not to be shunned, as we have all come from simple living that stems back centuries.  For those embracing the tiny house movement, there is much celebration and joy in doing so.

If you need assistance in choosing, and setting up your off-grid energy system, give us a call or email today.