The days are getting longer and many of us may be spending more time in our polytunnels. Spring is a time of increased energy, and a great time to get things done. Now could be a good time to consider thinking ahead, and installing lighting solutions. Having lighting in your polytunnel could allow you to make better use of it throughout the year, enjoying long summer evenings and even allowing you to get out and garden after work during the winter months.
Why Might You Need Lighting Solutions for a Polytunnel Garden?
Lighting can make it easier for polytunnel gardeners to make full use of their polytunnels, and to maintain them throughout the year. During the winter especially, when nights become longer, it can be a challenge to find the time to maintain a polytunnel, especially if you have a full time job. Being able to check on your plants in your polytunnel after dark can make it easier to stay on top of things and manage pests and disease.
Lighting can also allow you to enjoy leisure time in a polytunnel. A polytunnel can be used for more than just growing food. It can also be a place to enjoy some rest and relaxation. Having lighting in your polytunnel makes it possible for you to enjoy evenings in your polytunnel seating area, relaxing even after dark.
Finally, certain polytunnel lighting can be used to maximise yield. By using low-energy LED grow lights, you can extend the growing season and increase the quantity and types of food that you can grow. Being able to make up for the low daylight hours in the winter months can allow you to get started sooner with the growing season and get a head start on the year’s production.
Mains Electrical Power for a Polytunnel
If you would like to install lighting in your polytunnel, the first question that you will have to ask yourself is whether or not you will run mains power to the structure, or operate lighting off grid. The answer to this question will, of course, largely depend on the exact situation of your polytunnel – how far it is located from existing electrical infrastructure, and how much energy you will require to run the amount of lighting that you want.
Running mains power to a polytunnel is not always an easy or straightforward undertaking. It is important to make sure that you always adhere to any rules and regulations where you live, and it should go without saying that, when working with electricity, safety is paramount.
Larger installations for commercial enterprises will, of course, have to take into account the load on existing electrical infrastructure. Sustainability should also be of paramount concern for both domestic and commercial set ups.
If you do decide to run mains power to a polytunnel, then it could be a good idea to shop around for a green energy supplier, so you are not contributing to global carbon emissions.
Renewable Energy For a Polytunnel
With an eye on sustainability, and on cost, it could be a good idea to move away from mains supply and to consider the ways in which you, as a polytunnel owner, may be able to generate your own electricity to power your polytunnel lighting solutions. The initial investment in green electricity generation could be offset by bill reductions more quickly than you might imagine.
Solar Power Installations
The easiest and most common way to obtain renewable energy to power your polytunnel lighting solutions is with solar panels. Solar panels located outside your polytunnel will allow you to power a full lighting rig for a commercial or larger-scale set up. As a general rule of thumb, in average UK weather conditions, 1kW of south-facing PV solar panels can generate around 700-900 kWh of electricity per year. To put this into perspective, the average UK home currently uses approximately 3,700 kWh per year – though this can be significantly lower for energy conscious homes. How much solar capacity you need will, of course, depend on the number and energy usage of the lighting you plan to install. Remember, LED lighting uses significantly less power than traditional incandescent bulbs. Still, there is usually a considerable initial investment involved in a full-scale solar array.
However, it could be possible to make use of solar energy without a full-scale solar set up. A small solar panel of around 1 sq ft will generally generate enough power for a small light, sufficient to provide some ambient light within the space. Such a small solar panel can even be installed inside your tunnel, where space is limited, or security is a concern. While the cover of the polytunnel will reduce efficiency, generally speaking, clear plastic polytunnel covers will still allow around 90% of sunlight to penetrate. Small, portable solar panels used for camping applications could also be a solution for running a small light for a polytunnel garden.
Wind Power Generation
Solar power is not the only option for renewable electricity generation for your polytunnel lighting solutions. If you have a commercial set up or even a larger domestic situation, you could also consider erecting a wind turbine on your site. A roof mounted 1kW micro wind turbine will cost approximately £3,000 to install, but could provide cost savings over time. Larger scale installations will of course cost a lot more, but can generate much more electricity.
Small-Scale Hydro Electricity
One final renewable electricity option for domestic and commercial polytunnel growers is small-scale hydro electricity installations. If you are lucky enough to have a water course on your property, a small water powered electricity generator could be an option to consider.
Battery Powered Polytunnel Lighting
Smaller scale projects and domestic growers should not be put off by the cost of power generation installations when considering sustainable polytunnel lighting solutions. As mentioned above, small-scale portable solar panels could be a low-cost way to get lighting into your polytunnel. The sun does not always shine, however, and so the power generation can fluctuate. In order to increase the reliability of a small solar system, batteries and small power banks can help to even out supply and make a set up more sustainable. A small solar panel and power bank could be sufficient to reliably power small-scale lighting solutions in a polytunnel.
Lighting that is directly solar powered could also be sufficient for your needs. Some solar garden lights or camping lights will be powered up during the day and will store that energy in internal batteries and come on when it gets dark. You can find a range of options, from solar powered fairy lights, to ground lights and solar lanterns that you could use to provide a little light for your polytunnel garden.
Those on a limited budget could still provide light in their polytunnel by utilising battery powered portable lighting. There are a range of different camping lanterns and torches that could provide sufficient light to see in a polytunnel after dark. Some portable lanterns use solar energy, while other sustainable options are hand-cranked. Sometimes, such simple solutions are best for smaller-scale set ups.
Choosing Lighting Solutions for a Polytunnel
In addition to considering how the lighting solutions that you choose will be powered, it is also important to consider:
- How much energy the lighting you wish to install will require. (Remember, again, low-energy LED lighting is far cheaper to run and requires far less energy than traditional incandescent lighting.)
- How much light you will need. (This will depend on whether the lights are for plants, or for you, and on the conditions and daylight hours where you live.)
- How often lighting will need to be on. (Of course, grow lights will have to be on for a much longer period than lighting required for early morning/ evening/ recreational use. )
Check out our guides on LED grow lights to find out more about lighting solutions for growing plants, and how these can help you extend the growing season.
If you have anything to share about your own polytunnel lighting solutions, please comment below.
Elizabeth Waddington is a writer and green living consultant living in Scotland. Permaculture and sustainability are at the heart of everything she does, from designing gardens and farms around the world, to inspiring and facilitating positive change for small companies and individuals.
She also works on her own property, where she grows fruit and vegetables, keeps chickens and is working on the eco-renovation of an old stone barn.