The first step in the process is to determine whether to be attached to the Utility power grid (grid-tied) or not to be connected/reliant on the Utility (off-grid). There is no right or wrong answer to this question. If you are currently connected to the Utility, you will know this because you get the pleasure of sending them a check every month. Off-grid means that you are taking control of your energy needs and are going to become your own little utility/independent power producer, providing for 100% of all your electrical needs… No more monthly check-writing for you.
To begin, I’ve listed the four different types of systems available in order from least expensive to most expensive:
- Grid-Tied. Power generated from solar array offsets utility electrical consumption, no batteries, no back-up power, most efficient and lowest-cost system.
- Off-Grid. Remote, independent applications, solar array charges a battery bank and through the use of an inverter powers the home electrical equipment.
- Grid-Tied with Battery Back-Up. Solar power offsets regular electrical consumption, batteries store power for limited back-up, most versatile system.
- Grid-Tied and AC Coupled.
Check your utility bill to see if there is a fee called “Service Benefits Charge” (SBC) or “Renewable Portfolio Standard” (RPS). If so, you should be eligible to take advantage of an incentive program that is controlled by the New York State Energy Research and Development Authority (NYSERDA). Visit their website for up-to-date incentive level info.
I wish to point out that the majority of grid-tied systems do not have any batteries, and if you remember any one thing as you read on, please remember this: when the utility grid goes down, so do you. In other words your electricity goes out, despite the fact that you have 4kw of PV or wind on your site. This is to protect the utility lineman from being shocked by your system feeding electricity back into the grid as they try to repair the line. There are ways to provide your family with electricity and keep the utility workers safe at the same time. That’s where Solar & Wind FX comes in. While on the subject of the Utilities, you may wish to read our description of Net Metering.
Off-Grid is just that. You are off the utilities’ grid and are now in control of managing your own electricity production, as well as usage. The key word here is “usage.” I’m sure we all remember back to when we were kids and your dad was constantly telling you to turn the lights off in your room. You are no longer polluting the earth by using fossil fuels, nor are you concerned where we will put the nuclear waste from spent fuel rods. You have chosen to leave an inheritance to future generations that you cannot place a price tag on. Now there’s a Visa commercial for you. Priceless!! Not to mention how proud your dad would be. After all, he is due some credit. A good starting point is to know your annual Kwh usage. What I shoot for as far as qualifying and identifying a client for off-grid is a usage of about 6,000 Kwhrs or below, annually. If your usage is more, it will just take either more dollars and/or a good conservation strategy.
Obviously, there are many reasons for you to have a Renewable Energy (RE) system installed. However, we normally make this decision based on our back pockets. So just how far from the utility power is your building site? To give you a couple of examples, our Design Center is located at the end of a half-mile driveway. Back in the early 90’s, it would have cost us about $22-25k to have electricity brought up to our site. Well that was a no-brainer for me. Another site was about the same distance, and the client was quoted over $40k. They ended up with a $55k system for a 5,000 sqft home. Their thought was “why write a one-time check for $40k and still pay a monthly bill till the end of time?” So what if your utility quotes you only $10k and you need a $40k system? This is a decision you must make on your own. I can tell you that you will have cleaner power (simply put, your electrical appliances will last longer) and more reliable power than the utility will ever be able to provide. No more coming home and finding all your digital clocks flashing. Does anyone remember the ice storm of ‘91 or the Northeast power outage of ‘02? Did you know that the utilities have still not made the necessary upgrades to the grid system’s infrastructure to prevent it from happening again? Do you remember buck’a’gallon gasoline? How long before electricity prices catch up to the rest of the world? Our American appetites for electricity continue to grow, despite an outdated and overburdened power supply and distribution system.
The major difference in an off-grid home is that we use a set of batteries to store your electricity for times without sun/wind. In a grid-tied system, the utility grid is your battery; basically an infinite battery (that is until the utility goes down). In off-grid systems, we use wet lead acid batteries, similar to that which you have in your car or truck. However, the batteries are much larger and are designed to put out energy over the long haul, as opposed to the one in your car/truck, which is designed to output a lot of energy over a few seconds for starting purposes. Good news for off-grid projects: for the first time ever, you can take a 30% Federal Tax Credit on your project. See Incentives and Tax Credits below.
Grid-Tied with Battery Back-Up
This is the same as a grid-tied system, but unlike a grid-tied system, you have batteries so that when the utility goes down for whatever reason, your lights will still stay on. Now generally I would suggest installing a set of AGM batteries over lead acid, as they are better suited for always being at or near float (system) voltage. To learn more on battery types, select this link: Batteries 101. Any time you add batteries, you add cost to a project. And frankly, there are very few installers that have any kind of experience with batteries. After 18 plus years, I’m still learning new things about them, especially as they age.
Grid-Tied and AC Coupled
Is the most expensive of all four systems. This type of system is generally installed years after a client has already had a grid-tied system in place, and primarily because they want to have back-up power for those times when the grid is out. The reason that it is the most expensive system is that it requires duplicate equipment. For example, the grid-tied inverter is just that; it is for grid-tied only, and not designed to be used with batteries. Now we must add to your system an inverter that is designed to be used with batteries.
Still unsure as to what to do, either grid-tied or off-grid? I personally would like to see everyone become off-grid electrical users and never have to worry about electrical reliability or what next month’s bill will bring. Surprise! And the greatest by-product of being off-grid is the awareness and responsibility of your own electrical usage brought to you each and every day. On the other hand, if you are already attached to the grid, then I would suggest having us design a system that would allow for possible future expansion and movement towards going off-grid. To put it simply, take the State’s incentive/tax credits monies, and then after three years you have the option to go completely off-grid. Why? In order to get the NYSERDA incentive, one of the requirements is to provide electrical production data for three years. After that, you can choose to do whatever you would like. This means that your obligations to NYSERDA are complete after three years. If we design a system with the intentions of going off-grid in the future, you can then pull the plug on the utility and become your own private utility. Be aware that if the design is as such, the overall system cost will be higher. You now have the knowledge, and we hope you will use it to move towards power independence.