diy solar

diy solar

Energy Conservation

Lt.Dan

Solar Wizard
Joined
Dec 25, 2020
Messages
3,528
Location
Tulare, Ca
Hey y'all, this forum and the people on it have a wealth of knowledge that has helped me tremendously over the last year or so. I see so many threads from the basics to hooking up a solar setup, on how to maximize solar output, efficiency talks on different inverters and how to get the most for your money. But I'm curious if there's any threads that are dedicated to instead of making the most solar power you can, but rather the best things you did to conserve energy usage and take that 15kW solar array that you thought you need, down to 8kW.

Anybody got any good ideas outside of the normal "change out your light bulbs to LED"?

From mild to wild I want to hear your story!
 
Energy not required is the cheapest and cleanest energy there is and so ways to reduce consumption in the first place should always be part of system planning.

I think there is a corollary to this - how to shift discretionary loads to operate when energy production is available and/or to adjust loads so they adapt to the available solar production. In this way you make better use of the solar PV output when it is actually generated and thus may not need as much battery storage capacity. Arguably this is perhaps even more important given adding storage is expensive relative to adding solar PV.

On the energy consumption front, the big ticket items are those which involve using or moving heat, typically space heating and cooling and water heating. So these are the two areas which should take a significant portion of your focus.

For space heating and cooling the thermal performance of the home is the most important factor, and that's mostly about insulation and draft proofing but also about strategic shading or unshading as the case may be. For existing dwellings that's about a range of retrofit options for achieving better thermal performance of the ceiling, walls, windows and doors. For new builds it's about better design from the ground up.

Reverse cycle air source inverter heat pumps are very efficient ways to heat and cool relative to other methods. There are ground source systems as well but they tend to have more limited application and are very expensive.

For water heating, then it will depend on how your water is heated now, but the most efficient method is with a heat pump. Modern air source heat pump water heaters are very good and can reduce the electrical energy consumption to 1/4 of that a typical resistive element heating tank would use.

Then there are all the electrical appliances - modern fridges, TVs, computers all uses significantly less energy than they did even just 10 years ago. Recently I replaced a 12 year old TV (I sold the old one as it was still working just fine). The new one is same screen size, better resolution and uses just 25 W while the old one used 145 W!

If you do need to use a clothes dryer (as opposed to hanging clothes on a clothes line so the wind and sun can do the job for you for free) then again heat pump units are much more energy efficient.

So when the time comes to replace appliances, check the energy consumption ratings and make sure you choose wisely.

You already mentioned lighting, and it makes sense to replace with LEDs when it make sense to. Lots of options for that.

If you have a pool (the home we bought had one) then pumps are an example of devices with long duty cycles for which much energy saving can be made. I replaced an older single speed pump with a modern variable speed model. The new one uses about 6 kWh/day less energy than the old pump. That's a chunk of energy saved right there.

In the past six to years we have manage to reduce our average consumption by 22 kWh/day. It's never one big thing but a raft of things. This is our progress to date:

MgQTys5.png


And we have much more to do. Our home has pretty terrible thermal performance. I upgraded ceiling insulation in one section but there is much more to do.

On the time of use front, we have also shifted discretionary consumption to daytime hours to take advantage of solar PV when it is produced. Pool pump is the most obvious one, but clothes washing (and if required the clothes dryer) are used in the daytime. Same for the dishwasher. Modern appliances have programmable start timers or delays so they can be set ready to start once the sun is higher in the sky.

My latest addition is a smart power diverter for our hot water storage tank. It monitors the available solar PV and adjusts the amount of power sent to the water tank's resistive heating element so that it avoids importing from the grid. The element is rated at 3.6 kW but if there is only 1 kW of solar PV energy being generated in excess of household loads then it will send no more than 1 kW to the heating element.

As more or less excess solar PV is available, it adjusts the power sent to the water heater up and down accordingly. The tank takes longer to reheat, but it will only use available solar PV to do the job. It is also smart enough to know that if it is unable to complete a heating cycle with solar PV by day's end, then it will supplement the energy deficit by using our dedicated off-peak power supply when it becomes available, usually around midnight.

Our imports from the grid are down 31 kWh/day:

akHn7QZ.png


I expect the solar PV diverter will see another 4 kWh/day shaved off our grid imports by preferentially using our solar PV instead of the grid.
 
Anybody got any good ideas outside of the normal "change out your light bulbs to LED"?
Stop using electricity for heating and cooling.
You don't need air-con, a fan will do.
You don't need hot showers, cold is good for you.
You don't need heating, wear more clothes.
Cooking can be done on propane.

My entire house is now LED (mainly rings to replace my circular florescents).
I have a timer switch on my freezer, off at 6am, on at 9am to save my battery a little.
Walk around your home and turn off all the lights your woman and kids leave on.

I use/generate 10 units a day, but currently monsoon has been raining non-stop for 4 days/nights, so my batteries paced up yesterday.
Very unusual weather, it's normally sunny enough to fully recharge every day.
 
Stop using electricity for heating and cooling.
You don't need air-con, a fan will do.
You don't need hot showers, cold is good for you.
You don't need heating, wear more clothes.
Cooking can be done on propane.

My entire house is now LED (mainly rings to replace my circular florescents).
I have a timer switch on my freezer, off at 6am, on at 9am to save my battery a little.
Walk around your home and turn off all the lights your woman and kids leave on.

I use/generate 10 units a day, but currently monsoon has been raining non-stop for 4 days/nights, so my batteries paced up yesterday.
Very unusual weather, it's normally sunny enough to fully recharge every day. I think you assume everyone lives in an area like you. Come over to where I live with a 6 month wet season. Average of 90% humidity, temps up to 44 celcius and 3 meters of rain in 6 months. You,ll soon ditch your fan!!!! Timer on a freezer? No thanks...I,m not that miserable.
 
My goal was to do it without losing any of the conveniences.
Using 10KW array and 21KWh of batteries I was able to go from an initial saving of 50% to 60% just by tweaking the Sol-Arks TOU settings. That won't help most people but I was able to get to 75% Savings by doing the following.

1) Better management of the Hot Water Heater. Meaning it is turned ON at noon when the batteries are fully charged and then Shutoff it off at night just before the first person Showers. If it is running low on hot water after the the second person showers then we turn it on again for 20 minutes for the third person. You can automate that with a HW timer.

2) Clean the AC units Evaporator coil and fan blades more frequently. I now do it 3 times per year.

3) Vacuum clean the Fridge Condenser coil and Fan with a nozzle attachment at least once every year. If you have never done it you would be surprised by the amount of built up back there that is making the Fridge a lot less efficient.

4) Do most of the Laundry on Weekends after the batteries are charged.

The batteries will trip in sometimes when clouds pass over but on most days they still end up at 100% SOC by 5pm. Another 10KWh of batteries and I figure I would use almost zero grid power on most days.

Here is Today's usage
20MayCon.jpg
 
Stop using electricity for heating and cooling.
? It's far more energy efficient than using gas for heating. For cooling there are not many alternatives and heat pumps represent the least energy consumption for the amount of heat moved. Some live in very hot/humid climates. Fans are not always sufficient.

Cooking can be done on propane.
Likewise induction cooking is more efficient than gas.
 
? It's far more energy efficient than using gas for heating. For cooling there are not many alternatives and heat pumps represent the least energy consumption for the amount of heat moved. Some live in very hot/humid climates. Fans are not always sufficient.
Totally agree, blowing hot air around does not make for a comfortable nights sleep.
Likewise induction cooking is more efficient than gas.
If you have enough batteries then yes but if you do not then Gas IMHO is better mainly because during a prolonged power outage it’s one less big drain on the system at night. I keep a portable single burner convection stove in the cabinets just in case gas goes out, which is very rare.
 
If you have enough batteries then yes but if you do not then Gas IMHO is better mainly because during a prolonged power outage it’s one less big drain on the system at night. I keep a portable single burner convection stove in the cabinets just in case gas goes out, which is very rare.
That's a different issue than the topic of this thread - energy conservation.

You are talking about electricity conservation at the expense of using another less efficiency energy source.
 
Efficiency also has to factor in cost efficiency as well as watt efficiency. Yes, an induction stove may be more efficient on a watt per BTU scale, but if a battery big enough to cook dinner costs $400 and $300 in panels and $150 in SCC to power and a bottle of propane costs $15 and lasts for a month, then the propane is a more Cost Efficient method up front as it would take 57 months (almost 5 years) of cooking to break even on the system costs (as an example).

That seems to be something people tend to ignore is that while a system that will last 20 years is great, but if you have to live in the cold and dark for 5 years to afford it then it's worth nothing.

As for reducing the power needs, insulation I find is the biggest one that will result in immediate benefits. Just from my personal experience when I insulated the floor in the right half of my cabin my diesel fuel consumption on my heaters went down 75% from 24gal/wk to 6gal/wk.

After that comes heaters of various types, be it house heat, water heating, food heating, etc are all energy intensive items. It takes a lot of watts to heat up water and more to heat up anything denser than water (like food) so that kills your batteries fast. Heat pumps, especially high efficiency inverter types, can make a pretty significant difference in the power used to heat and cool a house. They even have heat pump based hot water tanks that are supposedly very efficient if you live in the right climate and can afford them.

Wells are another big hit on power systems and going energy efficient right out the gate will do wonders on your system cost and usage. If you can use DC ground pumps and cisterns then that's less inverter you need to pay for and provide power to if you don't need to have the huge startup capacity that a more traditional deep water pump requires on startup. Plus the inverters for those pumps tend to be low frequency which have a higher standby draw that you have to account for.

From what I've seen, insulation and heat are the 2 big ones that maximize the efficiency of any system, then it comes down to all the paper-cuts that add up over time.
 
rather the best things you did to conserve energy usage
ways to reduce consumption in the first place should always be part of system planning.
This is true. There is a point where convenient habits exchanged for conscious different habits create noticeable differences;
how to shift discretionary loads to operate when energy production is available and/or to adjust loads so they adapt to the available solar production. In this way you make better use of the solar PV output when it is actually generated and thus may not need as much battery storage capacity.
I only vacuum clean on sunny days, full battery for example.
typically space heating and cooling and water heating. So these are the two areas which should take a significant portion of your focus.
Cooling is often an area people go to great lengths to accomplish at great expense. While it’s easy to argue hot climates can be life threatening, the fact is that it is primarily a comfort item.
Heating on the other hand is a definite need. And you can meet that banal need and yet not be comfortable (not warm enough).
When one adjusts their mind to properly address needs VS wants then it is possible to both reduce consumption and reduce related costs in currency. But this has become culturally an unfamiliar idea- we as a society spend inordinate amounts of personal investment as well as the currency or credit to achieve comfort- or perceived comfort. People in general have lost the ability to assimilate the idea of “a penny saved is a penny earned” and focus instead on the misguided idea of “can I make the payments.”
thermal performance of the home is the most important factor,
People can’t afford that. Though apparently they can afford a new lazy boy, prepared foods latest phone, 72” tv, and more car than they need. What is the number? 50% of Americans can’t afford to pay in cash for an unexpected expense of $1000?
Insulation isn’t seen as necessary…
Then there are all the electrical appliances - modern fridges, TVs, computers all uses significantly less energy than they did even just 10 years ago. Recently I replaced a 12 year old TV (I sold the old one as it was still working just fine). The new one is same screen size, better resolution and uses just 25 W while the old one used 145 W!

If you do need to use a clothes dryer (as opposed to hanging clothes on a clothes line so the wind and sun can do the job for you for free) then again heat pump units are much more energy efficient.
Proactivity versus convenience.
time of use front, we have also shifted discretionary consumption to daytime hours to take advantage of solar PV when it is produced. Pool pump is the most obvious one, but clothes washing (and if required the clothes dryer) are used in the daytime. Same for the dishwasher. Modern appliances have programmable start timers or delays so they can be set ready to start once the sun is higher in the sky.
Proactively choosing over convenience again
I expect the solar PV diverter will see another 4 kWh/day shaved off our grid imports by preferentially using our solar PV instead of the grid.
Opportunistically heating water makes a great deal of sense. Even at my latitude for half the year people could offset $40-$60/month so payback on watts with that can realistically be one season. Maybe electricity will soar to equalize the cost/btu of propane again. Who knows, but electricity with current local propane prices is much cheaper to heat water with right now. A byproduct of solar happens to be electricity that doesn’t cost anything if you are harvesting unutilized watts.

The word ‘efficiency,’ however is imho often wrongly used. Our personal economies are not made up purely of how efficient our hardware plant is, but also how rapidly money does or does not leave our checkbook. I trade off efficiency in several areas for lower currency expense. Seeking lower cost utility and ancillaries almost always carries a large component of improved efficiency but seeking efficiency as task #1 may result in such an upfront expense that it harms us economically or worse- we opt out and neither achieve energy efficiency nor dollar benefits.
 
Though apparently they can afford a new lazy boy, prepared foods latest phone, 72” tv, and more car than they need. What is the number? 50% of Americans can’t afford to pay in cash for an unexpected expense of $1000?
ZOMG! Are you saying I SHOULDN'T get a new iPhoneX100 and the new XXxB0xXXSSX!!! Are you crazy? I NEED my Facepage and Tweeter!! ?

The word ‘efficiency,’ however is imho often wrongly used. Our personal economies are not made up purely of how efficient our hardware plant is, but also how rapidly money does or does not leave our checkbook.
And I find that many times this is ignored. Sure on paper that uber-All-Victron-LFP-5ZillionKW solar setup will last 30 years, but if you can't afford the parts then you're not going to live long enough to save up for it as you freeze and starve to death in the dark. ?

The word "Budget" means two things and I find that they are both often ignored.

I trade off efficiency in several areas for lower currency expense.
The solar system you can get and use NOW is far superior to the solar system you CAN'T get any time in the foreseeable future. WallyWorld batteries are here NOW and LFP's are a week/month/3months/never available.
 
I find knowing what is using the power and when helps me conserve energy. My local power company really started raising rates this winter so looking for more power monitoring bumped up to the top of my todo list. I have tried multiple things. Kill-A-Watt units were my original go to power meters for the last 20 years, but they are pretty rudimentary, can be used for usage over time but if they are mounted behind something that doesn't really work. I tried Emporia Energy smart plugs for certain appliances, but was concerned that a fridge or freezer might get switched off by mistake. I finally moved to Wiser Home Square D outlets and switches a couple months back. SQR441U1WHW Duplex Outlet & SQR226U1WHW two/three way switches. They support WPA3 WiFi, the duplex outlet has one non switched outlet and the fridge is plugged into that outlet, both are power monitored. (from what i can tell they are the only one that monitors the non-switched outlet too, at this time)
Last week I installed the Wiser Energy Monitor (OEM Sense device). Jury is still out on that, but its showing progress. No WPA3 for that device, will require a new device so I bought one cheap on eBay.
You need that OEM sense device to get more than realtime and last 24 hours of use, that is all the Wiser Home app will provide from those devices.
I am going to buy a 4 pack of the Emporia smart outlets for the motorhome. I really like their app, the interface is pretty good. I just wish they could figure out WPA3, for some reason they told me they support WPA3, but when I couldn't get them to connect that way, they figured out they didn't have routers that supported WPA3 to test it. (not a real confidence builder when I learned that after a month of working with them) I wish they could OEM the Square D Outlets/Switches as their interface vastly superior to the Wiser stuff. -Bill

PS. Since I started proactivaly monitoring my power consumption I have been able to reduce my power bill from $225 a month to $175 a month (when not traveling)
 
have tried multiple things
Just poking fun no ill intended but have you saved as much money as you’ve spent? :)

I’ve never bought one of the killerwhat devices. However, 15 years ago, two teenage daughters, custodial single parent my electric was $35-$55/month whereas most others I knew in similar circumstances/house/people were $80-$150/month. Especially if they had an electric hawt watah heatah. One family, three kids, not a too big house was $200+, and my neighbor right now is $250+ and used over $3000 in heating fuel this winter.

A couple degrees cooler and a flannel shirt, turning out lights, not being a ‘consumer,’ and no couch time for TV has not only made me healthier physically and mentally, it’s saved me tons of money over the last 20 years.

I occasionally feel I am cynical about ‘efficiency’ because I don’t get what people do and compare that to me. Probably not a good perspective to allow oneself to stay under, but still: I wonder what I would have done at $150 electric bill when sometimes it was a struggle with a $50 electric bill?

Working two jobs to get by makes you feel vulnerable and motivates you to cut expenses; would I have slacked of with more disposable income? Probably not. I have been living far under my means for four years and I don’t waste anything, don’t frivolous spend, and don’t spend on convenience when I can spend less and meet the needs with mindset adjustment.

Yet I still shower everyday and have clean clothes and need to lose a few pounds.
 
This was one of the main things I had to keep in mind when building my off-grid home here in the north: I had to conserve energy because I barely have any in winter. This meant a few things:

- Yes, energy efficient devices everywhere. These come at an expense however. Take my fridge: 110kWh/year only, but it costs over 2k€. It's one of the most efficient ones available on the market right now.

- Heating is done with wood. There is no other way to reasonably use any other energy source off-grid in the middle of winter here. Large tanks of propane are just not a thing here. Pellets are expensive (surprisingly) and needs a supply as well. I supply my own firewood from my forest.
Conservation of wood means efficient gasification boiler and low temperature (underfloor radiant) heating and a masonry fireplace. All these things cost money up front, but compared to traditional older wood boilers you save 30% to 40% wood.

- Cooking is done on propane (small 11kg bottles) in winter, and induction in summer (or outdoor kitchen). The oven built in the masonry fireplace is used extensively in winter, and can be used exclusively in case there should be a propane issue.

- Cooling is done (but will be improved this year) with a heat pump, using the radiant underfloor heating system to cool. Plenty of power in summer and no Texas-like excessive heat makes this easy. Could I do without? Sure, but it increases comfort and doesn't really take more resources. It just uses more of the available resources I need anyway for other parts of the year (the amount of solar panels). Incidentally, the heat pump will also lower my firewood requirements in spring/autumn when there is sun, but it's cold.

All the other equipment uses as little power as possible, or can be turned off without impacting comfort short term (for example the underfloor heating has a battery back-up system that can run the pumps, gasification burner, etc. for at least 48 hours). Having alternatives for heating, cooking, etc. just in case something goes wrong is definitely recommended in off-grid situations. Conserving resources however does often mean an up front investment cost, especially if comfort is part of the equation.

Now you could argue that I don't need e.g. the fridge in winter since it's cold outside, and in summer I have enough energy so it doesn't matter. However one of the goals was to make this place comfortable as any other normal house. Putting on jackets in winter inside was not acceptable. I will also not give up on warm showers, and neither will my wife and kids :)
 
Just poking fun no ill intended but have you saved as much money as you’ve spent? :)

I’ve never bought one of the killerwhat devices. However, 15 years ago, two teenage daughters, custodial single parent my electric was $35-$55/month whereas most others I knew in similar circumstances/house/people were $80-$150/month. Especially if they had an electric hawt watah heatah. One family, three kids, not a too big house was $200+, and my neighbor right now is $250+ and used over $3000 in heating fuel this winter.

A couple degrees cooler and a flannel shirt, turning out lights, not being a ‘consumer,’ and no couch time for TV has not only made me healthier physically and mentally, it’s saved me tons of money over the last 20 years.

I occasionally feel I am cynical about ‘efficiency’ because I don’t get what people do and compare that to me. Probably not a good perspective to allow oneself to stay under, but still: I wonder what I would have done at $150 electric bill when sometimes it was a struggle with a $50 electric bill?

Working two jobs to get by makes you feel vulnerable and motivates you to cut expenses; would I have slacked of with more disposable income? Probably not. I have been living far under my means for four years and I don’t waste anything, don’t frivolous spend, and don’t spend on convenience when I can spend less and meet the needs with mindset adjustment.

Yet I still shower everyday and have clean clothes and need to lose a few pounds.
$50 less per month will have me in the black in 2 more months. Kind of like me cutting the cable in 2010 and putting up $450 of OTA TV antennas. Paid for itself in 4 1/2 months, and the last 12 years since paying back the antenna install cost has saved us $14,400 of cable fees. (And that doesn't include the $4300 in taxes I would have paid to to earn that $14k. -Bill
PS. In 2010 we were paying $100 a month for cable.
 
Efficiency vs $ is always an interesting exercise. Many variables. I was looking to replace my mini splits last year and ran the numbers on SEER ratings vs projected life kWh usage, it was a wash. The lower price of the lower SEER units plus the expected cost of power equaled the higher initial cost, lower consumption high SEER units. Weird, it’s almost like the manufacturers worked that out before setting their retail prices.

Also, when I was shopping for a water heater I found the best option was to buy cheapest electric one available and adding a couple extra solar panels to the array.

Recently my power company started charging a monthly fee for each kW of rated power for my solar panels so my 9 year history of ‘just add panels’ no longer works. Essentially they reduced the cost savings of solar by 50% with their new fee. It adds a level of complexity to my $/efficiency calculations.
 
Efficiency also has to factor in cost efficiency as well as watt efficiency.
Then you are changing the goal posts, which is your prerogative but you titled the thread "Energy Conservation".

The word ‘efficiency,’ however is imho often wrongly used.
To me the word has a very specific meaning when used in the context of discussion about energy.

It is very specifically the ratio of energy output over energy input.

It specifically relates to the laws of thermodynamics.

I find knowing what is using the power and when helps me conserve energy.
This is a really helpful factor - it opens eyes to the stuff that matters, one can use the Pareto principle to begin with, but not ignore all the smaller items either.
 
It specifically relates to the laws of thermodynamics.
The more I sweat the less I get paid? ?

To me the word has a very specific meaning when used in the context of discussion about energy.

It is very specifically the ratio of energy output over energy input.
There needs to be a ratio of output of finances to energy input as well. If there wasn't a $cost/energy ratio then there would be no demand for Growatt/MPP/Temank products because everyone would ONLY use Victron and Outback.
 
Hey y'all, this forum and the people on it have a wealth of knowledge that has helped me tremendously over the last year or so. I see so many threads from the basics to hooking up a solar setup, on how to maximize solar output, efficiency talks on different inverters and how to get the most for your money. But I'm curious if there's any threads that are dedicated to instead of making the most solar power you can, but rather the best things you did to conserve energy usage and take that 15kW solar array that you thought you need, down to 8kW.

Anybody got any good ideas outside of the normal "change out your light bulbs to LED"?

From mild to wild I want to hear your story!

Change your living patterns to get more out of the solar.

- Shower when lots of sun to heat the water; cold showers when no sun
- AC at night if you need it to sleep but try to live with only fan during the day
- Better insulation in the living area so you need less cooling/heating
- Look after your equipment so it's running at top efficiency - clean condenser coils, fans, etc.
 
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