On-Grid or Off-Grid Solar Power: What’s Best for Your Farm?
Farms have unique energy and water needs. So whenever people talk about solar power, it’s really important to distinguish between the needs of residences, commercial businesses, and farms.
But even within farming, such a diversity of farm types exists that you really need to break it down further. Is it a poultry farm? A livestock farm or ranch? An agricultural crop farm of some type? Is it a large commercial farm, or a smaller local farm?
Once you’ve considered your farm’s energy needs and decided to go solar, the next question is, should you get off-grid or grid-connected solar power? The answer depends on the purpose of the panels and your unique energy needs.
On-Grid Solar Power – Less Costly but Less Versatile
An “on-grid” or “grid-connected” solar energy system is one that’s tied in to the utility lines. This type of system has surged in popularity in the last 20 years, now accounting for about 95% of solar energy capacity worldwide.
However, in the US grid-connected solar power is now used for only about two-thirds of the capacity. The reason we have a higher share of off-grid solar power than the rest of the world? Lots of farms – even big commercial ones – use off-grid solar. See the next section for why.
But on-grid solar systems are the most common for one simple reason: They’re less costly.
Why do they cost less? There are two main reasons.
- Sell your excess power. When an on-grid solar system takes in more energy than that location needs, the excess energy is fed back into the power grid. This “sell-back” saves money for the owner of the solar panels. This is where “net metering” comes into play. Not every state offers it, however, and for those who don’t, on-grid solar loses one of its major cost benefits.
- Batteries not included (or needed). Because the solar system is connected to the grid and can draw power from the grid, even if the sun doesn’t shine for several days no battery storage is necessary. While storage batteries make it possible to have consistent power from off-grid solar panels, they do increase the cost.
Georgia does allow net metering, but does not require utilities to offer it. (See which ones do). And they limit residential solar systems to 10kW and commercial ones to 100kW. South Carolina allows unlimited net metering.
However, for most residential homes, 10kW is more than you need, so on-grid solar power is something to explore if you’re looking for the less costly option and like the idea of selling power back to the grid.
For small farms, it’s a different story, because they often need more than 10kW. Though if you’re a commercial farm, in Georgia, you get the higher limit. Look at the benefits of off-grid solar next, and then we’ll walk through some of the questions you should ask yourself to help decide which system is best for you.
Off-Grid Solar Power – Freedom and Independence (and Sometimes the Best Option)
Off-grid solar energy is just what it sounds like – totally unconnected to the power grid. So if the power goes out everywhere else, your farm keeps humming. And if it’s winter, all your neighbors will be over for hot cocoa.
As stated, off-grid is usually more expensive because you need battery storage. But for farms – this isn’t always the case. Here are three situations where off-grid solar may actually be less expensive.
- Remote water pumping. If you have a large storage tank for the water once it’s pumped from the well, you can feed your livestock or water your crops for a few days even if the sun isn’t shining. So for a solar water pumping system, you may not need the battery. You just need a big enough water tank to handle longer stretches of limited sunlight. See this article for more on remote solar water pumping.
- Fencing and lighting. For farms, these systems are often solitary and small. Running power lines to all the locations can be quite costly. And because the power needs are relatively small, it is often cheaper to just install small solar panels at each location.
- 60% lower cost for remote solar power. The farther away you get from the power grid, the more expensive it will be to install power lines and voltage boxes to reach the location. A Food and Agriculture Organization (FAO) study found that for off-grid water pumping that was one mile from a power source, a PV solar energy system would cost 60% less than conventional electricity. This includes both installation and annual operating costs.
If you’ve got water pumping or lighting more than a mile away, then the savings are even greater, because solar is a fixed cost not related to distance. To be clear – solar power is actually less expensive than grid electricity for many remote farm uses.
And of course, the other reason to prefer off-grid is good ol’ freedom and independence.
You don’t have to worry about the utility bill any more. You don’t have to worry about Georgia Power or the state government changing their policies on net metering, or increasing utility taxes. Off-grid power simplifies your life and your farm operations, and gives you predictable and long-term cheap energy.
Off-Grid or On-Grid Farm Solar Power? 6 Questions to Help You Decide
Now that you’ve read a bit about the benefits and drawbacks of each for your farm, here are a few questions you’ll want to answer.
1. Do my state and city support net metering? If not, then on-grid solar loses one of its two primary benefits.
2. How much power (in kWh) do I use each month? This will affect the cost of your solar system, since more panels mean more costs.
3. How many systems on my farm can be connected to solar power? Be detailed here. Think about lights, refrigerators, freezers, air circulators, food processing, feeders, fences, water pumping from wells and for irrigation, sprinklers, heaters, and stuff way out on the edges of your property like gates. Note: Consider questions 2 and 3 in tandem. You may find that solar power is a good option for certain systems on your farm, but not all of them. Or, you might want off-grid solar in some cases, and on-grid in others. How much power each of your systems require is a big factor in this.
4. Of those, how many are “remote”, meaning pretty far from any grid-connected power source? Even 100 yards away is a long way if you have to install power lines. It’s expensive. Call the utility and see how much it costs to do this in your area. Solar is often the more affordable choice for remote power needs.
5. How important is it to me to be totally disconnected from the utility lines? You can have practical or philosophical reasons for this. Think about your personal values on this. It’s not just about the costs sometimes.
6. How long are you willing to wait to recover your costs? For on-grid, this will happen sooner in most cases. But if you have a lot of remote power needs on your farm, then off-grid may pay off even sooner.
The key to making your money back with an off-grid system is high quality storage batteries. The longer your batteries last, and the more effectively they store solar energy, the lower your costs.
Coastal Solar has partnered with sonnenbatterie, which guarantees a minimum of 10 years or 10,000 cycles with their lithium iron phosphate technology. Even the best lead acid batteries only last about 3 years or 1000 cycles. The sonnenbatterie is the solar energy storage battery of the future. Read more about sonnenbatteries here.
Poultry Farmer Saves Big with Solar
Check out this poultry farmer who will recover the cost of his new solar panels in just 5 years. Click here to read his story and watch a video of the installation.
Have Questions about Your Farm and Solar Power?