Chris Bond | October 29, 2019

Takeaway: With solar cells dropping in price and battery systems improving all the time, there are considerable benefits to looking at alternative energy sources for your growing needs. Chris Bond provides an overview of what is out there for those curious about unplugging from the grid and taking power into their own hands.

Nearly all the components of a hydroponic system can be partially or fully powered by alternative energies. Any system that runs on electricity or battery power ---such as lighting, pumps, filters, agitators, and timers--- can be altered to run on off-the-grid power sources.

Not all energy sources are practical for all systems, and many may be too cost-prohibitive to implement with complete efficiency.

But for the majority of alternative systems, there is usually a DIY version or an online hack out there that can help you to grow your greens without using petroleum or non-renewable energy sources.

Join thousands of other growers who are already receiving our monthly newsletter.

The systems outlined below are just an overview of the different types of alternative energies available and should not be considered a how-to. Most of the energy systems will generate direct current (DC). An inverter is required to convert the DC into alternating current (AC) to be useful for most of the appliances that a hydroponic system runs on. Another option is to consider converting your components to be compatible with DC.

Solar Energy

The effectiveness of any solar energy collection system for your growroom depends on how much sunlight you receive and how large of a collection system you can install. If you can put solar panels on the south-facing slope of your roof that aren't blocked by any large shade trees, then you will likely have enough power for more than just your hydroponic system.

Many homes, especially older ones, aren't suited for this type of installation. Solar panels can be placed on other buildings or as free-standing units in your yard. Their effectiveness then becomes reliant on factors such as the time of year or amount of cloud cover in your area.

The benefit of adding a solar collection system to your hydroponic set-up is that solar panels and other solar collection devices continue to improve as technology and demand increase. Simple systems can be installed to manually (or automatically) turn to follow the path of the sun.

Other solar collection devices are designed to warm the water by heating the pipes instead of converting sun energy into a current. This system can either expel heat or simply reduce the amount of energy required to heat your water.

Solar has come a long way in the last 20 years and there is an application for almost every scenario. It is also a type of alternative energy that can easily be added onto. You could, for instance, attempt to power just one aspect of your hydro system and keep building from there until the entire hydroponic system runs on stored energy derived from the conversion of solar power into usable current.

Wind Energy

Most people can imagine the way wind energy works as the concept is fairly simple. As the wind blows, a rotor or turbine spins. The energy derived from spinning is converted by a generator into usable power. The number of materials used to create a wind turbine also makes the prospect accessible to many and encourages creativity.

Wind turbines can be made from parts of 55-gallon drums, old satellite dishes, canvas sails, and almost anything that can cup the wind and spin freely. But the difficulty lies in the actual application of harnessing the wind power on a small scale and its practicality. Both of these depend on your location.

If you have an open piece of land that is an acre or more in size, wind power may be practical. If you live in an urban setting, in one of the tallest buildings, and have access to the roof, wind power may be practical. In a typical suburban setting, however, only very small scale energy applications are usually worth your time and investment. In these environments, it may make more sense to try to power only a portion of your hydro system with wind and then store whatever energy it creates into a battery.

Hydro Power

Yes, you can run your hydroponic system on hydropower; that is, if you have access to a source of running water on your property. In a nutshell, a portion of the flowing water gets diverted into a pipe (conveyance) where it is delivered to a pump or waterwheel. This then converts the flow of the water into rotational energy. An alternator or generator then converts the rotational energy into electrical current.

This system could be modified to run on stored water from a reservoir, but most hydro power systems take advantage of the natural flow of a body of water.

The initial investment will vary greatly depending on both the distance from the water source and how many kilowatts (kW) the system will generate. Many farm-based systems can produce up to 100kW, but even a modest 10kW is more than adequate to power a small growing operation.

Geothermal

Using geothermal energy in your hydroponic system is not as common as using solar, wind, or hydro energies, but it is still worth considering. If you are already paying for the energy it takes to heat your growroom, or are in the position of building a new hydroponics system, it pays to employ geothermal heating if you can.

Basically, geothermal heating takes advantage of underground soil or water temperatures. It draws this heat up from the ground into your structure and greatly reduces the amount of supplemental energy need to heat or cool the space around it.

There are many downsides to geothermal. Even though the temperature underground is fairly consistent throughout the country, accessibility is not reliable. Even if you do live in an area where the Earth’s underground warmth can be used, you will be unable to take advantage of this technology if you do not own the building or possess the right to dig beneath it.

However, if it is an option for you, you should consider tapping into this geothermal energy. It has a relatively quick payback period; you should immediately see the cost of heating or cooling your hydroponic space reduces.

Bioenergy

Making your own biofuels to either power some aspect of your operation or to heat the space you are growing in is probably the least likely of all the alternative energies listed here.

It is worth exploring, however, as most people create enough organic waste to power such a system. Grass clippings, food scraps, animal manures, and other organic wastes can be put into a digester to create biogas, which is a renewable alternative to natural gas.

While not practical for most people at the moment, bioenergy may represent a viable way to generate much of the energy needed to run your growing operation—maybe even your entire household—as the technology gets more widely utilized in coming years.

Rain Harvesting

Though not truly an alternative energy, collecting rainwater belongs in a discussion of using alternatives for a hydroponic system. Like the wind turbine, rain harvesting systems can be made from a wide variety of materials—five-gallon buckets, food-grade containers, or any collection tank that can hold water. Multiple small containers can be linked in series so that as one fills, the overflow goes into the next.

Most plants thrive better in rainwater than from city or well water. A hydroponic system can be supplemented, or filled entirely, with rainwater. As with any water source, careful scrutinizing of the pH and EC levels are called for. It is also important to maintain periodic agitation to prevent the development of algae or promote the breeding of insects.

Extra Considerations

No matter the type of alternative energy you consider to power your hydroponic system, there are a few things to keep in mind. Permissions range widely from municipality to municipality and you will need to know what your area’s zoning laws allow for, what requires a permit, and what is forbidden under any circumstances.

If you are considering installing a wind turbine, there are likely building codes to follow. The same goes for the installation of solar panels and collectors. However, many small-scale ventures into alternative energy can be done without affecting your neighbor’s view or without constructing large structures.

If you intend to harness the power of any stream, creek, river, or public body of water, you will need to obtain the appropriate permissions and may need to invest in equipment or components that measure your water usage and prevent backflow into the streams.

If any of these strategies sound appealing, but you lack the requisite building or engineering skills, there are more and more professional companies springing up that specialize in alternative energy installations for almost any application. Some of these strategies may even offer tax incentives. Check with your tax professional before claiming any alternative energy credit first, however, as many such programs are specific around how to qualify.

Written by Chris Bond

Chris Bond’s research interests are with sustainable agriculture, biological pest control, and alternative growing methods. He is a certified permaculture designer and certified nursery technician in Ohio and a certified nursery professional in New York, where he got his start in growing.