On-Grid or Off-Grid?
Choosing the right home renewable energy system depends on several variable factors: space, weather, budget, personal requirements, and goals. I want to take you through the three main, consumer-friendly renewable energy sources (wind, solar, and hydropower) and discuss them in terms of the variables listed above. In doing so, hopefully, you’ll be able to establish the right combination of these three to suit your home and your needs. Keep in mind that these are not static technologies, but are constantly evolving and bringing innovations to the space.
Of the three powerhouses of renewable energy, solar power is, without doubt, the most space-effective. If you have a lot of land, you could consider planting a field of solar panels to maximize your potential output, but even if you’re in an apartment or small home, you can install panels on your roof, or even buy portable panels to use at your leisure.
Space only becomes a major consideration in terms of the amount of energy you’re looking to harness from the sun, since the more space you have, the more panels you can install, and the more energy you can harness. Nevertheless, even in small and medium-sized houses, an array installed on the roof should be enough to dramatically reduce your dependency on grid electricity.
Solar panels require sunlight to produce electricity via the photovoltaic process. However, that doesn’t mean that they don’t work in cloudy, rainy conditions. Often overcast countries like the United Kingdom and Germany fuel a decent portion of their total energy consumption with solar power.
The most advanced solar panels today – monocrystalline panels – can still harness sunlight even when that sunlight is hampered by cloud cover. True, solar panel electricity production can fall to anywhere between 50-80% of total potential on overcast days, but with a big enough array, even half-efficiency will do you (and the earth) some good.
Since this is the first time we’re coming to this variable, I should break it to you: the initial investment into any renewable array is going to be costly. However, since renewable systems are generally low-maintenance, longevous, and are designed to produce endless electricity for you for free if you’re able to cover the initial cost, the long-term payout is second to none.
Solar panels make for relatively affordable arrays. At roughly $100 per 100 watts, installing a roof array to power home appliances can end up costing less than a new couch, plus, you can carry out the installation yourself, saving you plenty of money on labor.
Requirements and Goals
What do you want to power with your solar array? What is the ultimate goal for your move to renewable energy?
You can expect your solar array to produce, on average, about 75% of its optimum output on a day-to-day basis (taking into consideration overcast days). Thus, it’s important that the array you install covers at least 135-140% of your wattage requirements (e.g. you need 100 watts from your panels, therefore you should ensure you install panels that can deliver 135-140 watts, since 135-140 x 75% = c.100 watts).
Furthermore, if you’re looking to stay on the grid, then it might be well worth procuring a pure sine wave inverter, which would allow you to connect your array directly to the grid. On the other hand, if you’re looking to go off-grid, you’ll need to invest in a high-capacity energy storage system, to ensure you’re able to use your renewable electricity day and night.
Unlike solar power, space is of absolutely crucial importance to you when considering investing in wind power. The more space wind has in leading up to your home turbine, the more kinetic power it’s going to hit the turbine’s blades with, and thus the more power the turbine’s generator can produce.
You can, of course, buy vertical-bladed wind turbines designed for small spaces. However, there’s no getting around the fact that these turbines are wildly less powerful than their ‘horizontal’ cousins, almost to the point of being ineffectual. To truly get the most out of wind power, you need to have a lot of empty, unobstructed land on which you can plant large, powerful horizontal turbines.
Like solar panels rely on sunlight, wind turbines rely on wind. The good news is that most modern, consumer-sized wind turbines begin generating electricity in even the slightest of breezes. It has to be a pretty breathless day before your turbine is put out of action. On the flip side, there is also a maximum operational wind force that domestic wind turbines can sustain, past which they will seize to function.
Perhaps more than sunlight, the wind is a pretty constant presence in our lives, and so turbines can benefit almost anybody, living in any part of the world.
Welcome to the cheapest of the three heavy-hitters in the renewable energy world. With $100 buying you, on average, between 150 and 300 watts, home wind turbines make for an even more cost-effective set-up than solar panels.
The only major downside is that, whilst solar arrays tend to come with the wiring, controllers, and sometimes even the batteries you need to complete the setup, with wind power your money typically only buys you the turbine. That means you’ll have to set aside extra cash for all the additional bits and pieces. Still, DIY installation is more than feasible, saving you the cost of labor.
Requirements and Goals
Wind turbines can deliver electricity just as reliably as solar panels can, and so you need only make the same considerations when determining what size, or how many turbines you need to power your chosen appliances. You can still run wind turbines directly into the grid via inverters if you like, or you can choose to store the energy they produce in batteries.
However, when it comes to on-grid/off-grid goals, there’s no denying that wind power is most viable for off-grid living since it’s only with off-grid that you’re likely to have the requisite space for the set-up.
And finally, we come to the least well-known, yet the most ancient form of renewable energy: hydropower. It may not be something you’d consider possible to install on a domestic level, but it is. Of course, there is one distinctly limiting factor: unlike solar or wind power, which relies on universally available resources, hydropower does require that your ‘space’ includes running water. If you don’t have a brook, stream, or river running through your property (to which you have some claim), you will not be able to install a hydro system.
Hydropower relies on the water cycle. Even if you have a stream running through your land, the effectiveness of your hydro generator will fluctuate with the seasons. If you live in an area prone to drought and flood, then you’re going to have to factor in extended periods during which your generator will produce nothing and periods during which you’ll have to be careful it isn’t swept away or destroyed. Hydropower works best in water sources with a fairly reliable, steady, and regular flow. One of the major benefits of a well-placed hydro system, though, is that unlike solar and wind a hydro generator can generate electricity 24 hours a day, 365 days a year.
Unfortunately, despite its many benefits, micro-hydro systems (as domestic hydro installs are known) are the most expensive form of renewable energy system, with a typical 1kW (1,000 watts) system costing around $8,000 for parts and labor. Put in terms similar to those we’ve discussed above, that’s around $800 per 100 watts. Of course, since a hydro system could generate electricity for you every second of every day, it also has the potential to pay out a much bigger return than wind or solar.
Requirements and Goals
Given the need to have running water passing through your property, the chances that you could link a hydro system to your home’s grid connection are slim. In reality, hydro-systems are much more suited to fully off-grid individuals with a lot of land and a high-capacity energy storage set-up. Still, hydropower generates a lot of electricity, and if installed correctly could arguably reduce your dependency on other energy sources more than wind or solar power would.
Hopefully, I’ve given you all of the information you need to start planning your renewable energy home system, be it small and on-grid, or fully off-grid.
My final note to you is this: rather than putting all of your eggs in one basket, I recommend that you build a renewable energy system combining at least two, if not all three of the sources available to you. That way, no matter the weather, you’ll be harvesting renewable electricity.
The right home renewable energy system should combine different renewable sources, but be weighted toward your available space, local weather, budget, requirements, and goals.