Fronius solar inverter and maximising self consumption
Fronius solar inverter and maximising self consumption
In this article we are going to have a look at how you can get the most out of your Fronius solar inverter by maximising your self consumption.
Power is quite expensive to buy from the grid yet if you have surplus solar power – that’s solar power you’ve produced but aren’t using- you don’t get paid much at all for it.
If you’re not going to be paid much for the power you’ve produced it’s in your best interest to try and use this power yourself by maximising your solar self consumption. With a Fronius inverter there’s a few things you can do to achieve this, starting with the Fronius data manager card, like this one here.
The data manager card is installed inside your inverter and allows it to connect to the Fronius Solar web monitoring portal by wifi or a wired network connection. Solar Web is a free service from Fronius and is a great tool as all the information from your solar power system will be saved and presented in an easy to understand graphical interface.
Another great benefit is that solar web can be set up to send you email alerts of any errors the inverter may have so you can sort out any issues quickly, which means your system will have as little downtime as possible.
With a datamanager card connected you’ll have all the information about what your solar power systems doing but to take this information to the next level you want to combine it with data about your power consumption, and to do that you need a Fronius smart meter like this one here.
The Fronius smart meter is installed in your switchboard and collects all your power consumption data and displays it on the Solar web portal so you can get a good idea about what power your using and when – and when this information is combined with your solar power production data it highlights what you can change in your consumption habits to maximise self use, such as having the pool pump running a bit earlier or turning the washing machine on later in the day.
Here’s an example from our office, as our office fridge isn’t opened after 5pm or before 6am we’ve recently set it on a timer so it turns off at 5pm and starts up again at 6am.
Here you can see the fridge load pulling in and dropping out all night long, but when we installed the timer you can see how our night time standby load has dropped substantially. Just that one little tweak is saving about $100 a year on our power bills as now the fridge is running on free solar power about 95% of the time.
I wouldn’t recommend ever doing this with the fridge in your kitchen at home but it’s certainly a possibility for any storage fridges and freezers which are rarely opened, as if there not opened and are relatively full they tend to keep their temperature quite well when turned off overnight.
When you have a Fronius datamanager card and Fronius smart meter setup there’s a great little function that you can use called the Fronius energy management relay. It’s a function on the data manager card that can be setup to automatically control loads such as pool pumps or hot water systems when certain conditions are met. Say for example you have a hot water system that has a 1.8kW element. We can set it up so that when the inverter sees that 1.8kW of power is being produced surplus to your consumption it automatically turns on the hot water, and if surplus drops below a set amount, say 1.8kw it’ll automatically switch off, ensuring only surplus solar is used to heat your water.
We set this all up through our special control box like this one here:
-it has a 3 position switch that you’d normally leave on auto to run automatically via the Fronius energy management relay, or off to turn the load off altogether, or a bypass mode which bypasses the energy management relay and turns the load such as your pool pump or hot water system on- full time – you would use the bypass mode if say you wanted to clean the pool or if you had visitors staying over and needed more hot water than usual. It’d also be helpful if there was ever a problem with the inverter and the energy management relay wasn’t running properly for whatever reason- as this bypasses it altogether.
The energy management relay also has a function to set a minimum run time per day which is really important for loads such as hot water systems as if you have a miserable day and your solar doesn’t have enough surplus power available you still want hot water! This function works by setting a minimum run time per day and a start time to trigger this function -for example it can be set so that if the hot water hasn’t heated for 3hrs before 3pm it will automatically be turned on to run for however long is still required for the system to run for 3hrs. This is important as it ensures you don’t end up having cold showers! If your using the energy management relay to control a pool pump the number of hours it runs on a miserable day isn’t nearly as important, so for a pool pump this feature could be left off.
Unfortunately at the moment the energy management relay can only be used to control one load, so either a pool or hot water system but not both, however you could have the pool pump connected to the energy management relay and use another device from Fronius to control your hot water called Ohm-pilot.
The ohm pilot is used for resistive loads which are pretty much heating elements as used in traditional electric hot water systems and things like heated towel rails and underfloor heating.
When any surplus power is available at all, even as little as 10watts the ohm pilot will send this surplus power to the resistive load it’s connected too! So you don’t have to wait until the whole 1800w of surplus is available as with the energy management relay, whatever surplus power you have will be utilised. This is a great way to use your hot water system like a battery to store your surplus power for later use as hot water.
Another great benefit of solar web with the Fronius smart meter that’s worth mentioning is that it gives you valuable information about your power consumption in relation to your solar production- this information will help you choose the right sized battery in the future, which is yet another reason why the Fronius smart meter is a fantastic addition to any solar power system with a Fronius inverter.
So you can see by the things we’ve covered that your Fronius inverter is quite a capable piece of equipment and with a few small additions can really help you maximise your solar self consumption which in the long run run will save you even more money on your power bills.
Thanks for watching this video, I hope it helps you get the very best out of your solar power system and if you like what you’ve learnt don’t forget to hit the subscribe button for more helpful solar power information from Gold Coast Solar Power Solutions.