Let me set the scene: you are at the end of your dock, book in hand enjoying the last of the days sun. You know you should be helping get dinner ready, but the sunset is just so perfect over the lake. You can smell a campfire starting a few cottages down the lake, and you think this is exactly what I needed after a long week of emails, meetings and construction problem solving. As the evening hush begins, you are suddenly startled by the noise of a loud generator, started because you don’t have hydro this far into the bush, and you need lights to cook dinner.
This is exactly what I didn’t want when we decided to buy an off-the-grid cottage in 2019 and were faced with a need to supply power (the previous owners had taken the existing generator with them). We had spent summers and winters at our parents’ cottages which used generators for power, and knew that they can be costly to purchase, require a constant supply of fuel on hand, and are noisy. There was also the physicality required to start a generator and the annoyance of having to turn the thing off at night before going to bed. So, it turned out that our first major project for the new cottage was setting up a more environmentally friendly and long term cost-effective solution to providing our cottage with the power we needed. If we needed to invest, we wanted to invest wisely.
Our simple solar system comprises of the following components:
What and how much power is required? Our cottage only required power for the lights, charging cellphones and the Nespresso machine (we like our coffee). We have a propane powered fridge and stove; there is no microwave, no heat system, and no other large uses of power. We swapped out all the light bulbs to LED bulbs to reduce the power requirements. Ultimately, our power needs are significantly less than those of a traditional home. So we calculated that we are able to generate enough power for to meet our needs with six 100-watt solar panels.
TIP for anyone setting up their own small system: If time is not critical, watch the flyers for major hardware stores, 100-watt and 150-watt solar panels are often on sale for 50% off. We were able to accumulate all our panels over time saving us approximately 20% on the total system cost.
The power generated by solar panels is DC (direct current) power, but appliances and electronics use AC (alternating current) power. In order to convert the DC power into usable AC power, we needed to include an inverter. We learned (through a little trial and error) that not all inverters are made equal. Some electronics require a pure sine wave (Nespresso machines, for example).
TIP: You should review the requirements of your electronics and acquire an inverter based on those needs, a pure sin wave inverter can be more expensive but may not be required. Our system includes a 3000-watt pure sin wave inverter.
Storage of the Power
Since the system is dependent on the sun to produce power, but we use most of our power at night, it is important to include a storage component in the system. We have a 12-volt system with a capacity of 420-amp hours. This is equivalent to approximately 5 Kwh – allowing us to run all our light bulbs for 50 hours! This has proven to be more than enough. We try to save the power whenever possible but not having all the lights on, or charging our phones during the sunlight hours, but we have never even come close to having dead batteries.
In addition to these major components, we also included in our system a charge controller to stop our batteries from overcharging and an electrical disconnection.
Overall, it will take us approximately 5 years for the solar system to be cheaper than the use of a generator, but if taken care of properly, it will be 10 to 15 years before we need to replace the batteries. For us, the solar system will be a good investment, but more importantly, we enjoy that the system is quiet!