Is your annual consumption going up?

[svetz]

I was looking at my energy data over the last 3 years and noticed consumption was increasing annually:

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Three years worth of data is fairly meaningless, so I wanted to check what others who've had solar longer are seeing. The right graph is a bit misleading as the $ is a simple MWh x the average utility rate for that year, so it only shows increased costs assuming no production changes. I used the annual consumption as the monthly values have a lot of variance (e.g., October 2021 was the highest October, then October 2020, and finally October 2022 was the lowest. Year to year, production has been relatively the same.

Update: Found a data error, now it looks a lot more like normal variation!

 

[fromport]

In 2019 added an extra EV
In 2021 stopped using natural gas, so all heating switched to electric.
In 2022 installed 24kWh of batteries
In 2023 will install heat pumps for cooling/heating to replace central AC & oil filled electric radiators/heaters.
Also will add a 2nd inverter with 40kWh more batteries

 

[aenyc]

Not sure what exactly your ask is. Are you asking about total electrical household consumption?
If thats the ask, then my usage is roughly the same. The prices per kwh however are significantly up.

 

[svetz]

In 2019 added an extra EV
In 2021 stopped using natural gas, so all heating switched to electric.
In 2022 installed 24kWh of batteries
In 2023 will install heat pumps for cooling/heating to replace central AC & oil filled electric radiators/heaters

So you're up, but you have good reasons for being up. Impressive conversion history!

Not sure what exactly your ask is. Are you asking about total electrical household consumption?

Yes, exactly. Unlike @fromport I don't have (or can't think of any) changes that might account for it. Possibly it's the F22 AC deteriorating and running longer.

 

[svetz]

Whew! I found an error in the data... now it doesn't look so linear and 2022 was a hot year here (most of our power is consumed by the AC).

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[klystron]

Possibly it's the F22 AC deteriorating and running longer.

I assume you mean the r22 refrigerant in your a/c system?

A few years ago we discovered we had a slow leak in our a/c system when we noticed that the temperature in the house was 1 degree higher than the thermostat setpoint, which had never been the case before; the system always held the temperature right on the setpoint. The system was still under warranty so the tech came out, found the leak and brazed it closed, and recharged the system. That month our electric consumption and bill were 50% higher.

Previous to this I had built a system to monitor our energy and water consumption on a daily basis using an RPi to query the electric and water meters for the data and then send it to me via email where I logged it into a spreadsheet. I decided to modify that system to monitor the health of the hvac system as well.

Today the monitoring system consists of an RPi to fetch data from the water meters and several wifi modules to monitor total electric consumption and hvac performance by looking at compressor current, temperature near the condensing unit, inlet duct temperature and humidity, and outlet duct temperature. The system keeps track of degree days, logs every cycle that the hvac system runs, and at the end of each day it emails all of that data to me where I use an automated system to populate that data into a spreadsheet, allowing me to monitor the health and state of the system as well as our overall energy and water consumption.

I also took the course needed to pass the EPA 608 exam in order to get the certification necessary to make it legal for me to purchase refrigerant and open the system if necessary to make repairs. I learned a lot about hvac systems in the process and putting the monitoring system together and making software improvements as time has gone by has been fun.

As to your case, you probably have a leak and if it's an r22 system it is going to be expensive to repair and likely more economical to replace with an r410a system.

Consumption per year [2019 was the year the leak was discovered]

2019 - 8216 kWh
2020 - 6371 kWh
2021 - 6436 kWh
2022 - 6474 kWh

 

[svetz]

I assume you mean the r22 refrigerant in your a/c system?

"F -22" refers to Freon 22 which is Dupont's name for R-22; you'll see it in older units. [ref] (although, it probably dates me more than the unit ; -)

...As to your case, you probably have a leak ...

If there was leak the coils would ice up, which it's not doing.

2019 - 8216 kWh ... year the leak was discovered
2020 - 6371 kWh
2021 - 6436 kWh
2022 - 6474 kWh

Thanks for that data! That's quite a bit;, any idea how long it was leaking? For example that would let us know if it's 2 kWh per month or year.

... likely more economical to replace with an r410a system...

I've been wondering that too, I've been toying with the idea of monitoring it so I can do an analysis on it.

 

[klystron]

If there was leak the coils would ice up, which it's not doing.

This only happens when the charge is within certain levels and once below that level the evap coils will no longer ice up because the evaporator is being starved for refrigerant. You may already be below that point.

Compressor current will decrease as the charge level decreases, but compressor current is also affected by ambient temp near the condensing unit and other factors. Generally, low compressor current vs rated for the conditions is an indicator of under charge, normally used to support other symptoms when diagnosing the problem.

Temperature difference between inlet and outlet ducts is also an indicator, but you must take into account the relative humidity of the air in the inlet duct as the difference will decrease as humidity increases since more water is being removed from the air.

The best way is to hook up the gauges and monitor the temperature of the liquid and vapor lines. In an older r22 system you will have a fixed orifice controlling refrigerant supply to the evaporator and the charge is adjusted to achieve the target "superheat" at the vapor line based on the manufacturer's specs.

Newer systems use a TXV to control refrigerant supply to the evaporator, and charge is adjusted to achieve a target "supercool" at the liquid line.

Thanks for that data! That's quite a bit;, any idea how long it was leaking?

Roughly from about Oct 2018 to June 2019. It was a very slow leak and took that long before the system could no longer keep up with the demand set point. Meanwhile, the number of cycles and duration of cycles was increasing and I had no way of knowing this was going on because I wasn't monitoring it at the time.

 

[MurphyGuy]

Yes, my annual consumption has gone up almost 50%, but not because of anything out of my control. We added more solar capacity so I can use more.
About 80% of our Michigan winter heating needs are now provided by the solar system. It won't keep up during the 30 days of deep freeze in the middle of winter, but the solar takes care of the rest.

The other 20% is provided by the wood stove. We went from burning 14 face cords a year to about 3.

 

[crossy]

Over the last 3 years our annual energy consumption has remained (very) roughly constant. Down a little last year due to less WFH.

Our expenditure on energy is a whole different ball-game

 

[upnorthandpersonal]

Going up, but only because I find more uses for all the power I can generate.

 

[svetz]

Our expenditure on energy is a whole different ball-game From 2021 Hawaii was the most expensive in the U.S. Interestingly, the average residential electricity rate in Bridgeport, WA was only 2.64¢/kWh [ref], nice to have hydro. Still, the U.S. is less expensive on average than some countries. I can see why a lot of people want to switch to switch to solar/wind. I was saving money when the rate was at 13¢/kWh. I was looking at the Florida number, those numbers don't include all the "extras" they tack on. My rate was just over 14¢/KWh in 2021 if you just divide the total spent vs. power received.