In last week’s article I wrote about the need to calculate your own power consumption before investing in any solar power proposal. This week I want to talk about how extending the timeline for your data set well in advance can help you to improve the data accuracy of your energy saving calculations.
Let’s face the reality – most people can’t afford to buy a solar power installation outright. The people who can afford it often times care so little about the dollars and cents it will save them that it isn’t even worth the bother. This article is written for those people who maybe sit somewhere in the middle – they are interested in solar power, and maybe just maybe can scrounge together enough dollars to make it viable – but in order to justify it need to know the specifics of how a solar power installation will achieve a suitable return on investment for them, and how that installation stacks up against other, more easily achievable savings options, such as putting money into their business or into Kiwisaver.
But what you can afford to do, regardless of how much money you have in the bank, is to begin to take steps to figure out whether solar power is right for you. Despite the abundance of new calculators available, this really comes down to the specifics of your own household energy use, and in making these calculations, there really are no shortcuts.
Recording Data Well In Advance Greatly Improves Your Data Accuracy
In order to be able to depend on the numbers, you really need to have captured them over a suitable period of time. I put it to you that in order to have a fairly safe calculation, the longer the better, and a year is optimal.
True, some years will have far more daylight hours on average than others, and energy use habits will vary heavily from one year to another. But at the end of one year of homework, you will have a realistic understanding of how the numbers fit together, and you will be able to make adjustments as you personally see fit.
I would go so far as to say that without this level of data accuracy, you probably don’t have enough ammunition to convince anyone outside yourself of the viability of your own home or business solar proposal.
Recording Data Well In Advance Improves Your Sensitivity to and Understanding of Price Fluctuations
One funny side effect of recording data over a longer period of time (ideally a year) is that it gives you a sort of sixth sense of how your household energy budget will be affected by fluctuations in power use.
While wholesale energy prices can swing rapidly up and down over the span of a year, retail prices often remain fairly static. This is because regardless of whether wholesale prices are high or lower, energy retailers are most of the time creaming it from sticky customers who are reluctant to change, and who sometimes don’t understand their own power bills in detail enough to switch retailers confidently. This has been remarked on with chagrin in the annual reports of many wholesale energy generators who basically think that the situation is so bad that the government should intervene:
“I note that over the last year wholesale prices earned by large generators fell by about 8% while those at (NZ Windfarms) fell by 13%. Whilst the wholesale market declined interestingly retail prices rose by around 1%. This idiosyncratic market behaviour puts all merchant generators at risk and suppresses the build out of existing wind farm consents pushing away the day that NZ can depend fully on sustainably generated energy.”
– Rodger Kerr-Newell, “Chairman’s Review”, New Zealand Wind Farms Annual Report 2017
As you record your hourly and daily consumption of power, you will naturally gain a realistic sense of how much you will be paying for those kWh. This will only serve to sharpen your understanding of your own power bill and improve your negotiating potential. The thing about having bullshit filters is that they are only good if you actually use them.
Moreover, you will gain an understanding of how little, if at all, retail energy prices tend to fluctuate over time, and how little, if at all, new retailer pricing models improve upon old retailer pricing models.
This will help to improve your confidence about solar power. It will lead you to realise that the more things change, the more they stay the same, particularly with regards to future energy prices at the retail level.
Recording Data Well In Advance Gives You An Idea of Seasonal Variability
This is an important thing to get across, that I suspect some people sometimes overlook. It’s important to make decisions on solar power installations based on a full year’s data, not just one or two recent energy bills. For most New Zealand homes, power use fluctuates so rapidly between summer and winter that a single month of data simply isn’t meaningful to anybody.
At our motel, for example, the amount of power consumption during summer months is roughly one third of the power consumption of winter months, and that’s if we really conserve over winter. Never underestimate the power cost of all those heaters, hot showers, and electric blankets.
One of the biggest in-built grievances I have about solar is that during the winter months, when you need free energy the most, you generally have the shortest, most overcast days where sunlight is the least available. On the other hand, during summer where you have an abundance of sunshine, you have little to no need for all the daylight power you’ll be generating. It’s important to be realistic about this – only by measuring your actual use and weighing it against generation potential for months of the year, will you be able to gradually piece together an accurate picture of how much good a solar power installation will actually do you.
Recording Data Well In Advance Helps You to Identify and Eliminate Outlier Power Use
One more reality filter to consider on the solar power front is the fact that certain short-term use, but high energy consumption devices will never really be covered effectively by solar power generation. A good example is a vacuum cleaner, which uses a high concentration of energy in a relatively short burst, something that the low-and-slow collection of solar power simply cannot cover without the use of a battery for reserve storage.
It is important to identify these power consumption spikes from specific devices, so that you can effectively remove them from the equation for your household energy savings in order to make the numbers more realistic.
All of These Factors Help Improve the Accuracy of Your Numbers
As I have said previously, what we are working towards is a relatively accurate depiction of a return on investment calculation of household energy savings from your own solar power installation, something that is not easy to capture from a typical calculator with standard inputs. We are also trying to avoid situations where these sorts of calculations simply get put into the too hard basket “just cos”.
The most important factor in all these calculations is how much a solar power installation will reduce your actual household power consumption. In other words, how much it will realistically save you over time. If we can express this is as a percentage of the total investment cost, this will give you a realistic idea, based on your own risk-return profile, of whether it’s really worth it.
Conclusion
Even if you can’t afford solar power in the immediate future, that’s no reason why you shouldn’t start doing the math on whether or not it would be useful to you. There are an abundance of useful calculators that can help you to assess the energy generation potential of solar. But more importantly than potential energy generation, is the potential of your own home or business energy consumption that you can divert or reduce by an effective and well-placed solar power installation.
