Aggregate / battery during a power outage?

[dagling]

We experience power outages a few times per month, now 10 minutes to several hours.

Sli has been in the 4 years I've lived here, does not seem that they are able to fix this problem, either in terms of knowledge or money.

Someone who can recommend a simple and straightforward way to answer this?

I wish that this solution connects automatically when we have a power outage, so I can still use electricity for lights and fans.

Would be nice if it also could drive all in the house, including 1-2 aircon.

What do you consider that such a solution will cost and how you can buy what you need?

[Crossy]

A post with a link to another forum has been removed.

However its advice was sound, long outages = generator, if you want it fully automatic you'll need a generator that can interface with an automatic transfer switch.

PM our member Genset, he's been selling systems for some years.

Do you have a budget?

A simple UPS with external batteries will run to a few 10's of k Baht, but won't run more than a few lights and fans for a couple of hours, a genset and the paraphernalia to run the whole house is more like 10's of k USD. And there's all the levels in between.

If you're handy with electrics and mechanical things have a look at this thread http://www.thaivisa.com/forum/topic/671221-build-a-low-cost-semi-automatic-generator-transfer-switch/

Moving to the electrical forum for focussed discussion.

[IMHO]

The problem doing a UPS is that you want t run the whole house - which means a LOT of money on inverters, and then again on batteries.

If you can be more selective about what get's backed up by a UPS it can start making sense though - e.g. fridges/freezers and essential lights only.

For whole house backup, a generator can be much more cost effective, and even basic ones can run 8 hours or more before refuelling.

[Crossy]

We have a hybrid system. A UPS keeps PC, lights and fans going but it's backed up by a generator which can run the bedroom aircon.

Genset starts within 30 seconds of the power going off but the UPS can keep a couple of fans going all night so we can stop the genset when we turn off the TV and go to bed (it's not the quietest beast in the world).

Future expansion to add solar and go almost totally off-grid.

[Crossy]

Running an AC on inverter and batteries means a huge investment on batteries and inverter.

Indeed, a 100Ah 12V battery discharged to 50% stores only 600 Watt hours (0.6 kWh) so two would run an average aircon for a whole hour

[Crossy]

I removed Arjen's earlier post

[keeniau96]

Re Crossy with the future system including solar, could you post diagram and component list? I have been serious thinking of same and have major respect for your advisories.

[Crossy]

Re Crossy with the future system including solar, could you post diagram and component list? I have been serious thinking of same and have major respect for your advisories.

The current plan is to use the smartest inverter I can find, presently in the frame is the 5kW variant of this one http://www.opti-solar.com/english/pt_SP_%20Premium.en.html which can manage the panels, batteries, genset and export excess energy to the grid. It's just over 2k USD at present.

Here's the manual SP5000 Premium manual-20160301.pdf

Currently this inverter is not on the MEA or PEA approvals list so I won't be able to (at least officially) use it in grid-tie mode. I may get around the restriction by installing an approved grid-tie system with the correct paperwork then arranging to swap the inverters once everyone is happy

[keeniau96]

Thank you Crossy, that is a very neat solar inverter. Several questions:

1. What battery do you use, presume it is a bank of something like gel-cell. How many amps total in the bank?

2. Currently you have generator and transfer switch? What are the specifics eg. make/model & ratings.

3. What is: MEA or PEA approvals?

[Crossy]

1. Currently we are using 2 regular 12V truck batteries (60Ah each IIRC) on a modified PC UPS (1,000VA) to run lights and fans when the mains is off and the genset stopped.

2. Details of our genset and transfer switch is here http://www.thaivisa.com/forum/topic/671221-build-a-low-cost-semi-automatic-generator-transfer-switch/ for the enthusiastic DIYer. If you are not confident of your DIY electrical ability I suggest you contact forum member GenSet.

3. MEA (Metropolitan Electricity Authority) and PEA (Provincvial Electricity Authority) are the power supply authorities, you will get your bill from one or other unless in a moo-baan that bills you privately. Any system that can export power to the grid (such as a grid-tied solar system) needs to be approved by the relevant authority.

The PEA list of approved inverters is here https://www.pea.co.th/vspp/Documents/Rooftop/PEA%20Inverter%20List/PEA%20Inverter%20List_updated%202016-03-18.pdf sadly at this time there are no hybrid or wind turbine inverters on the list.

There are several forum members who have run foul with PEA when installing grid-tie solar without the necessary paperwork, so it is important when going grid-tie that you have your ducks in a row. Once upon a time you could get away with hooking any old grid-tie inverter up and spinning your meter backwards, things are tightening up

[keeniau96]

Crossy, thank you very much, have been looking at your transfer switch post (all 3 pages) and will be doing something eventually. Leaning toward solar system as UPS for key items (BR a/c and the computer area), with enough battery bank to keep those operational for 24 hours. I have installed several fairly large solar rigs for boats but principal competence is in computer hardware, so think I can handle what I would like to have, with your info as a very good background.