I own a guesthouse in Muizenberg, Cape Town. We have plenty of wind, and sun and with that the corrosive salt air and the constant salty mist to cover solar panels. Will be looking for solutions on that later tho....

My plan is as follows:

Step 1) monitoring and measurement

Step 1a) Expanded solar water heating capacity

Step 2) Inverter and battery backup

Step 3) Solar generation

Step 4) Wind generation.

So for Step 1 this is the complete measurement and monitoring of our energy consumption. I have been looking at the home assistant (rasberry pi) setup to start building a monitoring system that can expand and basically record our journey. (we will be posting a-lot of the stuff to our social pages, so the initial measurements are key for us)

Any advice on what meters work best for this? Setup recommendations etc? There is a lot of noise on the internet when trying to source a compatible meter, that can integrate into home assistant and expand with our system as we go.

I also want to integrate some temperature measurement, and water flow measurement as we build out the system, so any advice on these kinds of sensors / flow meters would also be helpful.

During our initial phase we will also be adding to our solar water heating capacity, as this will be low hanging fruit to improve efficiency (any recommended installers in the Cape Town area - the past few I have used have been complete let-downs).

During winter we consume about R10,000 per month on electricity alone... so I am done with supporting this Eskom kak.

I also suspect that my old 3-phase meter is over-reading and I am being hugely overcharged - so will need to replace that to a more modern 3 phase unit (our initial measurement will hopefull verify if we are being overcharged or not.)

Looking forward to posting pics, getting involved and seeing what can be done.

Bear in mind if you want to dispute your meter your own measurements will not be taken into account. At your high use it will be good if you get a company in with calibrated instruments to do the measurements and provide you with a report. Even then it can be a lengthy battle to get a new correct meter.

Effergy consumption systems work great. Eastron also make a great meter to measure every possible value. Search on YouTube for videos and model number.

Edited August 23, 20223 yr by Scorp007

Maybe goes without saying, but I suppose you'll be giving special focus on monitoring the guest rooms. In Winter the heating might not be used sparingly if the bill is someone else's problem.

18 hours ago, wolfdogcat said:

During winter we consume about R10,000 per month on electricity alone... so I am done with supporting this Eskom kak.

This is not necessarily an Eskom problem. Maybe there's lots of heating of rooms going on? What temperatures are the geysers set to? How many guests? Is lots of guests taking lots of nice long, hot showers on somebody else's dime a possibility?

I would suggest that in the meantime you check the temperatures on your geysers and maybe turn them down a bit, and fit some low flow shower heads. 

Sorry if this sounds sarcastic or mean. It's regular advice given to people here who want to go solar. Get a handle on your consumption first. Try to figure out where it's going, if there are reductions you can make without too much adverse impact on your lifestyle, simple things like not turning the geyser up too high, like not burning lights in rooms that aren't used, like fitting low consumption (LED) lamps throughout, like using gas for cooking. 

It's important to do this as best you can. because when you want solar installed, any half-way decent installer should be asking you about consumption and how much and when so that they can sell you an appropriately sized solution.

But when you are running a guest house it's a lot more difficult. Different people with different habits all the time. 

Maybe put in gas water heating as well.

How close are you to the guest house? If you go for gas then you have to have somebody handy to keep the cylinders full.

Back up your own home first, and claim the costs of running the guest house as a business expense.

18 hours ago, wolfdogcat said:

Step 2) Inverter and battery backup

Step 3) Solar generation

Step 4) Wind generation.

If you do step (2) smartly, you will make (3) and (4) easier. Start off with an inverter that can accept solar AND wind, and that has sufficient capacity for what you are aiming for. LIFE batteries will cost you a significant amount more up front, but will last a lot longer.

20 hours ago, wolfdogcat said:

During winter we consume about R10,000 per month on electricity alone...

Best waves in Muizenberg are North West winds which means Winter and the worst weather... nothing like a long hot shower while taking off your wetsuit after a surf 😁 You should maybe consider going for a gas geyser, so you can have hot water all day on demand, I'm not sure if a solar geyser will handle the 'traffic'.

I'd read more on wind generation before spending money as turbines don't like strong, gusty winds, I don't think CT is very well suited for wind generation in general. Open, flat areas with consistent winds are usually better.

On 2022/08/22 at 8:00 PM, wolfdogcat said:

Any advice on what meters work best for this? Setup recommendations etc? There is a lot of noise on the internet when trying to source a compatible meter, that can integrate into home assistant and expand with our system as we go.

There are 2 types of meters. Clamp meters where you do not need to change wiring and inline meters where you need to route the electricity through the meter.

The Efergy meters are clamp meters but I have no idea if they integrate with home assistant. I see there are some nice clamp meters on amazon that integrate into home assistant but they are always out of stock.

Sonoff makes an inline din-rail meter with a 63A breaker, this might work well for measuring a single phase. I have some sonoff devices integrated into home assistant.

With regards to energy usage you will very likely find that a large percentage (50% or more) goes into heating water. Since your water requirement schedule is not predictable and you need large amounts of water heated a heatpump will save a lot of electricity. Install a commercial unit. It should pay for itself within 2 years. Next insulate all hot water pipes to minimise losses. Lastly throw out all the old geysers that are not B energy efficient rated, they simply leak money.

Once you have plugged the black hole sucking up your cashflow look at solar, solar is expensive and your payback will be anything between 5-10 years

Thanks a mil for the input guys. For a bit more clarity... 

We run a 200ltr main geyser, with 5.5kw het pump (no element connected). This is fed by a 150ltr geyser, with geyserwise circulating through 32 evacuated solar tubes with  a 3kw element coming on in the mornings and evenings.

And it's not enough... 16 people showering 2 times per day, with a fully operating laundry... water heating is our main issue. This I am aware of. We also can't limit a paying customers water... the negative reviews would be far more detrimental than eskom pricing.

The power meter we have is a rotating disc 3 phase meter. Noah had one on the ark. It will need to be changed, but I am wanting to check if there is a discrepancy first, and if there is, then get some big guys involved to fight it out with council.

Measuring the current consumption as a starting point will also enable us to measure the impact of our energy saving initiatives as we go. A bit of a marketing thing also. 

From what I can tell the Efergy system seems like the best starting point. Has the ability to integrate with Home Assistant later, and comes as a complete package out the box, and can monitor up to 5 circuits at the same time (bonus)- the only problem is that all the suppliers seem to be out of stock, with a wait time of 6-8 weeks.. any inside track on where to get?

I have also looked at the Victron EM24, Iammeter, and nanoview - but not super impressed (although might go with nanoview for water metering)

Also going to change out geyser element for one of those PCT stainelss steel ones (they say 15% saving on energy..... but not sure how much to believe... once the metering is in place, I will be able to tell you. )))

Thanks for all the input so far, glad to be part of this awesome forum, and hope to post some progress soon (well sooner than 6-8 weeks)!

 

9 hours ago, wolfdogcat said:

And it's not enough... 16 people showering 2 times per day, with a fully operating laundry... water heating is our main issue. This I am aware of. We also can't limit a paying customers water... the negative reviews would be far more detrimental than eskom pricing.

Still think about low flow shower heads. I have these at home, and they reduce flow whilst giving lots of small, strong jets, so it doesn't feel like you're getting a short ration. It's the usual game: Pay up front and save in the long term.

Reducing flow will also reduce your water bill.

I must say that I hadn't thought of the reputational damage angle. But we've been using RST's for oooh... 15, 16 years now, and they make me happy by saving water and they make the wife happy because she likes the sensation of the multiple strong jets. So this may be an option you want to explore.

9 hours ago, wolfdogcat said:

We run a 200ltr main geyser, with 5.5kw het pump (no element connected). This is fed by a 150ltr geyser, with geyserwise circulating through 32 evacuated solar tubes with  a 3kw element coming on in the mornings and evenings.

I think your bill is accurate, your setup is lacking.

You do not store enough hot water. Your 32 Evacuated tubes have nowhere to store the energy.

Disconnect the 3KW element. Completely. This is waste of energy

Let the EV tube pre-heat water when sun is available but give it at least 400 liter (or more) storage (even if they only reach 50 degrees this is perfect).  The pre-heated water contains free sun energy and does not cost anything. This should flow into the tanks heated by the heat pump, here you need another 400 liter (at least depending on the max draw eg. 8 guests showering at the same time). The heat pump should be able to maintain the required temperature and the cost is fairly cheap to run as you will be getting 3X the heat for each unit of electricity spent (compared to the electrical element). Your heat pump is also a bit on the small side but this can be fixed by storing more hot water on the pre-heating side. 

I would connect the elements on the final outflow tanks (heated by the heat pump) and switch it on to assist the heatpump if the temp drops below a pre-defined temp (that guests would complain)

In short ask an engineer to do a design and calculate the number of BTUs that you need. 

 

 

11 hours ago, wolfdogcat said:

Efergy system seems like the best starting point

The problem is it only measures current, no Voltage, thus no real idea about power consumption and no power factor neither, so the Efergy in my opinion is a nice starter toy, but the information it provides is to be taken with a handful of salt...

Thanks guys, 

1 hour ago, Kalahari Meerkat said:

The problem is it only measures current, no Voltage, thus no real idea about power consumption and no power factor neither, so the Efergy in my opinion is a nice starter toy, but the information it provides is to be taken with a handful of salt...

Any recommendation on something else then?

23 minutes ago, wolfdogcat said:

Any recommendation on something else then?

This lot is probably one of the better options out there, but not sure it can integrate with ha...

@Kalahari Meerkat is right that it is not perfect, but its not terribly out, so it depends what you need. You can change the voltage setting to try and dial in results a bit which I did do. For me, as an overall indication of what is happening it was fine. For the first couple of weeks that I used it last year I compared the meter and the Efergy daily and got the following:

 

Some great info, thanks!

I am really unable to find a meter that is both fit for purpose, and available - seems everyone is waiting on stock for Efergy.

Any other off-the-shelf items that anyone can recommend to get started? Don't mind replacing it later... I have looked at the Iammeter.. but reluctant to spend R5k on a take-a-lot product - although it does have the cloud based platform to get graphical data from? might have to go with it for the next few months while Efergy stock comes in.

I checked out the "Open Energy Monitor" thanks - https://openenergymonitor.org/  - looks like it works and runs on MQTT which can integrate with HA... but again, its not in stock - Rasberry Pi system, and apparently nobody has those! 

Still looking )) (Anyone want to sell their Efergy meter? )) 

 

 

Quote

So for Step 1 this is the complete measurement and monitoring of our energy consumption. I have been looking at the home assistant (rasberry pi) setup to start building a monitoring system that can expand and basically record our journey. (we will be posting a-lot of the stuff to our social pages, so the initial measurements are key for us)

If you OK with a bit of tinkering, then the Sonoff may be of interest:
https://www.sonoffafrica.co.za/

• Sonoff Power Monitor Pow R2 - 15A - for lower power devices (not geysers)
• Sonoff Smart Geyser Switch - 25A - for geyser
• Sonoff Smart Stackable Power Meter - Main Unit
• Sonoff Smart Stackable Power Meter - 4Relay

You can flash these with Tasmota can connected them to MQTT (no cloud) and HA.
https://tasmota.github.io/docs/

There are other Smart Plugs that have power monitoring out there. Most run Tuya and store data in the cloud.
I recommend plugs that can be flashed with Tasmota.

Add a database (eg PostgreSQL/InfluxDB/MySQL via HA Recorder and create dashboards in Grafana.
Works a charm.

TIP: Use containers on your RPI

20 hours ago, wolfdogcat said:

Any recommendation on something else then?

https://www.milney.co.za/products/power-monitor-high-amp

Lots of people love their Shelly products, I think they also do mqtt out of the box.

 

On 2022/08/25 at 1:30 PM, system32 said:

• Sonoff Power Monitor Pow R2 - 15A - for lower power devices (not geysers)
• Sonoff Smart Geyser Switch - 25A - for geyser

Sonoff devices are really awesome and once flashed to tasmota you have total ownership of your data
Also Visia powerplugs - can also flash tasmota
I already have my crypto rig(Powr2), lounge(visia), kitchen(visiax2), lights(Powr2) and geyser(powr3) done.

On 2022/08/25 at 1:30 PM, system32 said:

Most run Tuya and store data in the cloud.
I recommend plugs that can be flashed with Tasmota.

Agreed, anything that can be tasmotised is the way to go

Stay away from Tuya powered devices(being sold by all the retailers in SA), they now use proprietary wifi chips which cannot be flashed anymore.
Of course this only applies if you do NOT want to share your data with Big Corporates.

Guys, this is epic information. Thank you.

 

With regards to the tasmota stuff, I definitely like it, and think this will be the best in the long run. I have looked at some other units also, and thinking to go with an off-the-shelf solution to start the monitoring, while I dust off the engineering degree, and go through the learning needed for HA.

My thinking as follows (shout if there are any red-flags you can see?):

IAMMETER - off-the-shelf, and available through take-a-lot (you'd be surprised what the leadtime on most units are) - its MQTT (although not sure it can be flashed for tasmota - it does seem to be able to read tasmota.. so should be some compatibility), but given that it can integrate directly to HA, I am happy enough with that - and the price tag of 5k for the 3-phase unit is doable. It also has its own cloud dashboard to start with. This will keep me monitoring while I go through the learning curve of the tasmota / HA stuff

I also looked at MONNIT devices - love them - but the price tag is to steep for me from the onset - need some eskom savings first. ))

Keep the comments and solutions coming. Thanks guys.