The most common reason a quote for off grid solar is ridiculously high is because the system is designed to run everything, even on the worst day of the year. This happens because of a lack of communication with the customer about what they want, what they need, what's economically viable, and what conservation efforts they’re willing to undertake.
If you have ever asked for a quote for off-grid solar, most likely the first question you were asked was “what is your calculated power usage?”. The entire quote is then based around this one estimate, and a system that can always support it.
One thing customers are never told when getting a quote for off-grid solar? What they can do to lower the cost. We believe this is a massive disservice to a customer.
We believe that the customer should be presented with all the information so that they can make an informed decision about what is best for them. GridFree is not just a solar company, but an off-grid lifestyle company. This is why we prefer to consult with you on a solution that works best for you, both for your energy needs and cost concerns. This might mean switching heating, cooking, and water to gas/woodburning/other alternate sources, installing a generator that runs a few days of the year, or developing a few energy conservation habits.
To better convey the idea of how a little energy conservation can save you a lot of money, we collected solar statistics for NZ from NIWA, to calculate how much sunlight is produced throughout the year (based on an average of the last five years).
Peak sun hours represent how much sunlight there is during a given day. The easiest way to think about if this: if you have a 100W solar panel, on a day with 1 hour of sunlight, it will produce 100Wh of energy. On a 6 peak sun hour day it will produce 600Wh of energy. (Watts multiplied by sunlight hours equals Watthours.)
| Peak Sun Hours | Days with this much sun or more |
| 0.25 | 365 |
| 1 | 362 |
| 2 | 339 |
| 3 | 301 |
| 4 | 239 |
| 5 | 169 |
| 6 | 111 |
| 7 | 54 |
| 8 | 15 |
The lowest recorded sunlight in one day was 0.25 peak sun hours, this means every day of the year produces at least 0.25 peak sun hours. This same calculation was done for each level of peak sun hours. If we look at 3 peak sun hours, we can see that there are 301 days of the year with at least that much sun. Therefore, if you have a 100W solar panel, you know that you will produce at least 300Wh for a total of 301 days or 82% of the year.
We can then use this to explain what you can run on each of our kits. To give people an idea of which kit would suit them, we provide information on what can be powered on 3 peak sun hours. This is an example of what can be run on the Bach Kit:
| Peak Sun Hours | Days with this much sun or more | % of Baseline Power Generated |
| 0.25 | 365 | 8% |
| 1 | 362 | 33% |
| 2 | 339 | 67% |
| 3 | 301 | 100% |
| 4 | 239 | 133% |
| 5 | 169 | 167% |
| 6 | 111 | 200% |
| 7 | 54 | 233% |
| 8 | 15 | 267% |
The other thing of note is that for half of the year you will also have more than double the power you need.
The 38 days where you can only use 2/3 energy might look like this:
The 23 1/3 days like this:
For these 23 days, it may require you to switch some devices off overnight.
The other thing to remember is that this is not 23 consecutive days, but just the total days during the year that are cloudy and stormy. Some of these days may occur during summer or spring, when there will be ample energy in the batteries to rely on anyway.
This table shows roughly how the days with 1 or 2 peak sun hours were distributed through the year.
| Peak Sun Hours | Month | Number of Days |
| 1 | March | 3 |
| 1 | April | 1 |
| 1 | May | 3 |
| 1 | June | 4 |
| 1 | July | 4 |
| 1 | August | 3 |
| 1 | September | 2 |
| 1 | October | 2 |
| 1 | November | 1 |
| 2 | January | 1 |
| 2 | March | 7 |
| 2 | May | 7 |
| 2 | June | 5 |
| 2 | July | 5 |
| 2 | August | 4 |
| 2 | September | 3 |
| 2 | October | 1 |
| 2 | November | 1 |
| 2 | December | 4 |
The other consideration is how many consecutive days there are with low sun. Looking at the same NIWA estimate data, there are only 8 times a year where there are more than 2 consecutive days of low sun - with 2 occurrences of 5 consecutive days with low sun, one of 4 days, and the rest 3 days. Learn more about how to deal with that here.
Here is what the system would cost if you were building it for the same energy usage, based on different sunlight hours.
How Much are Solar Panels? - Prices
When thinking about solar panels and pricing, if you wanted to never worry about power conservation with the example usage above, you would need to spend at least $23k. If you were installing solar in a bach you only use during the summer, you could base it on 6 peak sun hours, and you would only need to spend $6000.
| Peak Sun Hours | Days with this much sun or more | System Cost | Recommended Kit |
| 0.25 | 365 | $23,000 | Lifestyle Kit + extra panels + extra batteries |
| 1 | 362 | $15,000 | Freedom Kit + extra panels |
| 2 | 339 | $8,500 | Bach Kit + extra panels |
| 3 | 301 | $7,500 | Bach Kit |
| 4 | 239 | $7,500 | Bach Kit |
| 5 | 169 | $6,000 | Tiny House Kit |
| 6 | 111 | $6,000 | Tiny House Kit |
| 7 | 54 | $4,200 | Weekend Warrior Kit |
| 8 | 15 | $4,200 | Weekend Warrior Kit |
If you are ok with these restrictions you will save over $13k in this scenario. These figures get even more extreme when you are looking at larger off-grid solar systems, or systems designed to support electric ovens and water heating (we recommend switching these to gas/woodburning).
Off-grid solar quotes are so high because they’re designed to work on even the lowest sun days, and often account for appliances that don't make sense on solar, like electric ovens. But they don’t need to be. A simple change in your habits to conserve energy for just a few days can mean thousands of dollars in savings.
Get in touch with us to get a free consultation on your off-grid solution - email us at info@gridfree.store, message us on Facebook, or call 90 218 5533.
If you've got a quote for an off grid solar system and you'd like to see how it stacks up against ours, you can send it to us here.
