Victorians – Why have you never heard of interval data?
In Victoria, you can get smart meter interval data from your energy provider with no hassle. But it is likely that you have never heard about it before. So, why should you care to know now?
A little background..
In Victoria, few years ago, the state government decided to make smart meter the new “standard meter”. And, according to government’s website, 2.8 million smart meters were rolled out by the end of June 2014, replacing the old analog meter. Whether you liked it or not, you had to make the switch to smart meter.
Interval data is very helpful to study how you use energy throughout the day. If you are considering solar for your home or business, you may care to know a little more about it. Let’s get to it now…
What is an interval data?
Interval data is the information about your energy usage in every thirty-minute, 24/7/365. Your smart power meter records this information and automatically transmits that to your energy provider where it is stored and made available to you at your request. You can also download this data yourself by logging into your distributor’s website. The service is free of cost to you.
Energy is measured in kilowatt-hour, kWh, so interval data is a numerical value in kWh. It looks something like this.
As you can see, your consumption is reported for every thirty minute interval for each day. An average Aussie home consumes about 17 kWh of energy each day.
How to get your interval data?
If you are seriously considering solar energy for your business or home, your time spent getting interval data from your energy provider is well worth it. But, don’t worry. It doesn’t take long at all.
You can request the data either from your retailer (the one who bills you) or from the distributor (from whom your retailer buys the power in order to supply to your home). There are total of five distributors in Victoria and all of them provide your interval data on their website. Just log in and download. It’s that simple. Few retailers also make this data available on their website; others make the process too complicated. In that case, simply skip the retailer and jump to the distributor’s website.
Here are the links to the five distributors’ website from where you can download your data.
Powercor/Citipower are the latest to join the forces. They didn’t have the online portal until last August. But they lived up to their promise and didn’t disappoint.
Note: You can find the name of your distributor in your monthly bill; top right/left.
How to read interval data?
A smart meter records over 17000 values (17520 to be exact, two for each hour) during one year period. That is a lot of data to interpret into something meaningful if you don’t have the right data tools, although Microsoft Excel is good enough if you have some experience. Below is visual of hourly usage for a business that operates in the day.
You can always ask the solar company you are dealing with. They should be able to interpret that data for you. Some solar companies don’t like interval data, specially for smaller residential projects, because it adds more time to the transaction.
Who can benefit the most from interval data?
Anyone who is considering solar either for home or business, but have limited knowledge about their own power consumption habit, can benefit the most from interval data.
Advantages of using interval data in solar sizing
1. OPTIMIZE THE SIZE OF SOLAR SYSTEM
First, here is how the size of a solar power system calculated,
Size = Your daily energy consumption / Peak Sun hours(PSH)
As you can see, the bigger consumption value results in larger system size. We want the consumption value as precise as possible. Anything more means an oversized system that results in longer payback period of the solar system. Less means a smaller system that doesn’t save you enough on your power bill. Interval meter data gives flexibility in determining that consumption in two ways:
– Only include those hours of the day that are relevant to solar energy.
– For businesses, exclude off-day(s) of the week when averaging out for the daily consumption.
First one is straightforward. What I mean in the second point, which only applies to businesses, is that some businesses close on weekends while others stay busy at this time. Interval data has data for each day. This gives the flexibility to include only those days that are relevant to calculate average for daily consumption. Simply averaging out over 365 days works for homes but can be misleading for most businesses.
Sometimes businesses like to work backward. Instead of installing the size they need, they may choose to optimize the size of a system for specific payback period. Interval data can be very useful in such cases as well.
2: FORECAST A MEANINGFUL SAVINGS
Hourly interval data helps analyze your past usage pattern and simulate the future consumption based on that. Based on your historical data, it helps to forecast which hours of the day demand more power, and which hours are “quiet”. This helps determine how likely you are to consume solar electricity produced on-site; the holy-grail of savings calculation.
Here is a bar diagram (from a sample case I chose for this article) that shows power demand (green) and solar production (yellow) for the first six months of the year.
If you see yellow bar shorter than green for any hour, it means demand exceeds supply and in that case you import from the grid to make up. And when yellow bar (supply) is taller, excess supply is exported to the grid (Net metering) for very little financial incentive.
This sort of detail savings analysis is key in commercial systems, less in residential.
Any savings forecast derived from monthly summary data (using your monthly electricity bill), on the other hand, is ALL based on arbitrary assumptions.
Like with any other investment, knowing the return of solar investment is critical. And, more accurate, the better.
Even after rebates and tax incentives available for small businesses, solar power system can be a heavy investment. A high level savings forecast can be often misleading.
In Victoria, serious business owners can request solar companies to optimize solar system size based on interval usage profile. This can be an important exercise for systems above 10kW. There is too much money on the table.
In Victoria, you already have smart meter and your interval data is just few clicks away. If you want to make a wise solar investment, this is a complete no-brainer. Go to your distributor’s website, download the data, and work with the solar company to optimize your need.
If you live anywhere in Victoria and need help looking at your interval data, send it to my email at poudel at solarwisely dot com dot au. I will email back with cool graphs. It’s a free service and your information will be confidential. I do this because it’s fun for me.
I hope I was able to get you excited about interval data today…