Solar system design - collect data for usage profile

[gamb00ler]

We're having a 10Kw solar system installed by professionals to be shared between two households in two new colocated houses.  We won't have anything with a constant load such as a pool or water features.  The load will be primarily be daytime, evening and overnight A/C for a retired couple household and additional evening and overnight A/C for a typical working couple, plus normal laundry/bathing and cooking.

 

Initially we'll have what will presumably be insufficient storage (8.2Kwh) to cover overnight usage.  We won't have previous bills to guide us and the effectiveness of the design considerations (ceiling insulation/AAC 20cm) to keep the heat out are as yet unknown.  I would like to start collecting more detailed power usage data than is provided on the power bills.  Are there devices available that can record the power use for each hour of the day?  Of course I would prefer one that doesn't require me to do a manual meter reading every hour.

 

My computer experience is extensive but pretty dated at this point but I have an extra Raspberry Pi to work with.  My software development knowledge is limited to '90s technology.  I do have experience with computer communication devices and protocols as well as device drivers.  In a pinch, I could probably add some ability in something newer.

 

Also there is potential for another solar installation on our son's restaurant.  For that system it is unclear how much storage would be cost effective.  In the restaurant, most of the power draw will occur after sunset because there is a hot pot on each table plus A/C.  The current rough estimate is that electric consumption is about 1Kwh per customer.

 

I warn you that my knowledge of power transmission, distribution and residential wiring is indistinguishable from zero.

 

Advice from those with greater knowledge and experience is appreciated.

 

 

Edited November 1, 2022 by gamb00ler

[KhunLA]

I think you're way under powered for houses. 

Restaurant, with hotplates, you're going to need a lot of ESS kWs.

 

For home use, can go by the units you're using now, and depending on present building construction, I would plan to use what you're using now in kWs, if all things, AC use & m², being the same.  You'll probably use less, but good safety margin.

 

We went from a poorly constructed / insulated townhouse to present well built / insulated house, more space.  Rental; 1 old small AC, and usage at rental was 500-700 PEA units/kWs.

 

New build, 2 inverter ACs (13&24BTU),   New house haven't broke 500kW monthly yet.  Probably will next month if we hit 20 a day.  Now average 15kW a day, and ACs cool about 90m² for 10ish hours.  First 6 weeks, we were conservative with use.  Now more normal usage.

 

We have 20kW for overnight (1700-0730hrs), and use about 7kW now.  Most of that before midnight.  That's after dinner, and no heating elements being used.  Minimal AC use, laptop/TV (65"), till midnight, along with 2 frigs, and a fan, on the whole time.

https://aseannow.com/topic/1268214-solar-8kw-hybrid-inverter-w10kwh-essbattery-not-diy/

 

[gamb00ler]

8 minutes ago, KhunLA said:

I think you're way under powered for houses. 

Restaurant, with hotplates, you're going to need a lot of ESS kWs.

 

.....SNIP

 

We went from a poorly constructed / insulated townhouse to present well built / insulated house, more space.  Rental; 1 old small AC, and usage at rental was 500-700 PEA units/kWs.

We deliberately went low on ESS because of budgeting concerns for the construction.  Adding more ESS will be very simple but still expensive, unfortunately.  We also wanted the UPS functionality from the start.

 

We hired the solar installer long before completion of construction so that any wiring required could be completed with ceilings still open.

 

Our rental is a very poorly designed, 35 year old heat trap.  Our electricity bill here is 500-900 units/month.  The air conditioner is also probably not that efficient.

 

 

For the restaurant system, it's easier to make it cost effective because the rate paid to the landlord is 7฿ per unit.  It is likely that space for the panels will be the limiting factor for that system.

[Gweiloman]

You can purchase smart plugs on Lazada with electricity monitors. This will tell you your instantaneous draw as well as hourly consumption of the appliance that you plug into it.

[Crossy]

We don't have the same usage profile being more constant loads, but this is our generation from 10.6kWP for the last 12 months.

 

 

There are plenty of electronic meters with RS485 / ModBus which you could interface with your Pi and do by the second energy logging.

 

Have a look here https://aseannow.com/topic/1161970-an-internet-enabled-solar-power-monitoring-system-another-project-from-crossy-labs/

 

[Gweiloman]

34 minutes ago, Crossy said:

We don't have the same usage profile being more constant loads, but this is our generation from 10.6kWP for the last 12 months.

 

 

There are plenty of electronic meters with RS485 / ModBus which you could interface with your Pi and do by the second energy logging.

 

Have a look here https://aseannow.com/topic/1161970-an-internet-enabled-solar-power-monitoring-system-another-project-from-crossy-labs/

 

Way too complicated for me. I plug the smart plug into my wall socket and the appliance into the smart plug and read the result off the app on my phone lol.

[Crossy]

2 minutes ago, Gweiloman said:

Way too complicated for me. I plug the smart plug into my wall socket and the appliance into the smart plug and read the result off the app on my phone lol.

 

If it does the job then why go complex? ???? 

[JAS21]

 The air conditioner is also probably not that efficient.

 

Buy a new inverter air con unit ... you would be amazed at the reduction in your monthly electric bill. We bought Daikin FTKM18SV2S not  the most quite on the market but cheap to run.

[gamb00ler]

1 hour ago, JAS21 said:

 The air conditioner is also probably not that efficient.

 

Buy a new inverter air con unit ... you would be amazed at the reduction in your monthly electric bill. We bought Daikin FTKM18SV2S not  the most quite on the market but cheap to run.

I'm not in the habit of buying a new air conditioner for use in a house I'm renting...

 

The air conditioner is fairly new but not from a well known manufacturer.  Plus either the control unit is messed up or the inside air temperature sensor is out of whack.  The compressor won't start even if the temperature set via remote is several degrees below the current temp.  I have to futz around with power and the mode setting until I feel cold air blowing out, then I can change the settings to something reasonable.  Setting the remote temp to 27 takes the room temp to about 24.  Increasing the remote temp to 28 results in the compressor shutting down requiring more remote control futzing (and cussing).  So our choices are 24 (or colder) versus sweltering.

 

Good thing we're moving shortly.