Is solar battery storage worth it?

Qyburn

Martyn1981 said:

Plus, there is an added factor, regarding export limits and the DNO's. Typically you can export 3.68kW, and if you ask the DNO they let you go a bit higher - I've got a 5.9kW limit. But, by having a DC side battery on my 3.68kW inverter, I've now added more panels taking the PV up from 3.58kWp to 6.725kWp, and should be able to avoid clipping (where the inverter caps output to 3.68kW on the AC side) by directing the excess DC generation to the battery.

I appreciate this isn't a common situation, but the battery actually allows my property to produce more green leccy pa than it otherwise would be able to.

Going forward, new installs with a DC side battery (and a hybrid inverter), may be a partial solution for properties that can't get a higher export limit, thus allowing bigger PV systems.

Same with us, we have 8kWp of panels with a 6kW inverter, maximum allowed by the DNO. On a sunny day our battery is fully charged from clipped solar, energy that would otherwise have been wasted.

An extreme example ..
 

little_acorn

As a complete novice to this topic, I would be interested to know the physical size and weight of a battery.

Qyburn

little_acorn said:

As a complete novice to this topic, I would be interested to know the physical size and weight of a battery.

Solaredge 9.7kWh is 790mm wide, 1179mm tall, 250mm deep. 119kg.

St1ngyman

Having taken the plunge this year, one factor came out of the battery storage that wasn't mentioned everywhere I looked  (except 1 site in Australia I found 1 month after installation. 
The operating temperatures of the standard batteries is from 0-50 degrees C so on a lovely sunny cold day I was getting over 3KW of energy generated and all going down the grid. the batteries don't charge at zero temperatures and are limited charge up to 5 degrees to prevent damage. The company that sold it didn't mention this and all are similar, apart from the higher cost Tesla, LG, etc that have a form of temperature control.
I still kept the batteries and feel it is worth it in my situation due to most consumption being evening time despite the annoyance at this missed information.
I also have a friend in the car industry that drives electric cars, who said he didn't know this and it explained why he lost 60 miles range overnight from a fully charged car. 
 

Reed_Richards

St1ngyman said:

I also have a friend in the car industry that drives electric cars, who said he didn't know this and it explained why he lost 60 miles range overnight from a fully charged car. 
 

I don't think that's normal for an EV.  But you do have to use the battery for heating the car interior so your range will drop in winter.  But not overnight unless you are preheating the interior for a few hours.

Exiled_Tyke

Reed_Richards said:

St1ngyman said:

I also have a friend in the car industry that drives electric cars, who said he didn't know this and it explained why he lost 60 miles range overnight from a fully charged car. 
 

I don't think that's normal for an EV.  But you do have to use the battery for heating the car interior so your range will drop in winter.  But not overnight unless you are preheating the interior for a few hours.

I thought the cold battery issues is what 'battery conditioning' is all about: cars warming the battery to better take charge.  On my car if the sat nav is set to a charger and it's cold then battery conditioning switches in time for arrival at the charger.   But then again I may have completely misunderstood and be wrong! 

Magnitio

Exiled_Tyke said:

Reed_Richards said:

St1ngyman said:

I also have a friend in the car industry that drives electric cars, who said he didn't know this and it explained why he lost 60 miles range overnight from a fully charged car. 
 

I don't think that's normal for an EV.  But you do have to use the battery for heating the car interior so your range will drop in winter.  But not overnight unless you are preheating the interior for a few hours.

I thought the cold battery issues is what 'battery conditioning' is all about: cars warming the battery to better take charge.  On my car if the sat nav is set to a charger and it's cold then battery conditioning switches in time for arrival at the charger.   But then again I may have completely misunderstood and be wrong! 

Battery conditioning takes place on certain cars prior to arrival at a fast-charger to ensure the battery is in the right temperature window for it to maximise the charging rate. This can also occur when the car is started in cold weather in order to get the battery up to a reasonable temperature to perform adequately.

This is a bit different to the issue of estimated range reducing when the weather is cold; this can be due to the car taking into account the requirement for heating the cabin space. Again, this will depend on the car.

Exiled_Tyke

Magnitio said:

Exiled_Tyke said:

Reed_Richards said:

St1ngyman said:

I also have a friend in the car industry that drives electric cars, who said he didn't know this and it explained why he lost 60 miles range overnight from a fully charged car. 
 

I don't think that's normal for an EV.  But you do have to use the battery for heating the car interior so your range will drop in winter.  But not overnight unless you are preheating the interior for a few hours.

I thought the cold battery issues is what 'battery conditioning' is all about: cars warming the battery to better take charge.  On my car if the sat nav is set to a charger and it's cold then battery conditioning switches in time for arrival at the charger.   But then again I may have completely misunderstood and be wrong! 

Battery conditioning takes place on certain cars prior to arrival at a fast-charger to ensure the battery is in the right temperature window for it to maximise the charging rate. This can also occur when the car is started in cold weather in order to get the battery up to a reasonable temperature to perform adequately.

This is a bit different to the issue of estimated range reducing when the weather is cold; this can be due to the car taking into account the requirement for heating the cabin space. Again, this will depend on the car.

Very helpful. And just to add - there is of course a little reduction in range by using heat to condition the battery- my car manual warns about this.  Also I very hepfully get two range readings: 1 for the current use of heat/a/c and a second estimate for if I turn it off. - Is this a usual thing? I never know what's unique and what's now common to all/most EVs.

PDoffwiththeBBC

Hi,

    A much cheaper way of "storing" your excess solar output is to use an immersion diverter. We use a Solic unit which diverts any excess power to an immersion heater element  in the hot water tank . We turn off our hot heating system from end April to mid Sept. It works really well. In addition, in the winter months , it still augments the gas system , by raising the temperature , a little , meaning you don;t use as much gas. It cost  £150 to fit , about 7 years ago.

Qyburn

PDoffwiththeBBC said:

Hi,

    A much cheaper way of "storing" your excess solar output is to use an immersion diverter. 

Surely that only makes economic sense if your normal water heating costs you more than 15p/kWh. Otherwise you're better "storing" you excess in the grid.