Energy from conventional sources is becoming more and more expensive. As a result, people are increasingly interested in using energy when costs are low – for example when their PV system is producing abundant current. However, being able to use energy to get the most out of it also involves a number of other considerations. This article describes smart energy management with the Sunny Home Manager.
What exactly are energy management systems, and why are they useful?
Energy management systems work in several ways to optimize energy consumption. They help people use energy as efficiently as possible – thereby reducing their overall consumption. By intelligently controlling energy flows, they also reduce the load on the utility grid. The greatest advantage for users, however, is that they help lower their electric bill by timing energy use. Probably the simplest way to achieve optimal energy consumption is to pay attention to it, avoiding unnecessary use or to at least use energy when costs are low.
But that’s where the difficulty lies; many people rarely read their meter. An energy management system helps them use energy wisely by recording and displaying energy flows so they know how much electricity they use at any given time. They can also easily see when they typically use the most, or which appliances draw the highest load.
In addition to its monitoring and analysis functions, an energy management system can start appliances at just the right times to optimize consumption. There are two ways to do this. The simplest is to control the supply of electricity to the appliance (such as a heat pump) with an on/off switch. In the ideal situation, the energy management system can even communicate with each appliance – picture, for example, a washing machine with a USB connection.
Sunny Home Manager – for intelligent energy consumption
That’s exactly what the Sunny Home Manager does. Connected to as many as three energy meters, it always knows the energy demand and power generation capacity. It also knows the weather forecast for “its” PV system, so that it can estimate how much energy the system will generate in the hours ahead. In addition, it knows the time-of-use electricity rates. Taking this and other data into account, it can decide when it is more economical to use self-generated current and when it pays to feed it into the grid.
The Sunny Home Manager clearly displays all this information on the Sunny Portal status screen. With this free online service from SMA, users can view their PV current generation and household energy status anytime and from anywhere (Internet access required). Of course, the service works not only on a computer, but on smart phones and many other Internet-ready devices. With Sunny Portal, users can even turn household appliances and electrical devices on and off remotely. In addition to displaying household energy flows, Sunny Portal features a very simple visual prompt that indicates the best times to use additional energy – for example, operating an electric lawnmower or other high energy loads when excess energy is available.
The Sunny Home Manager can operate up to 10 SMA radio-controlled sockets, independently activating simple appliances such as a dishwasher or washing machine. This takes advantage of a feature often available in modern appliances: After a power outage, the program resumes exactly where its sequence was interrupted. The SMA radio-controlled socket simulates this “outage.” The Sunny Home Manager then ensures that power is restored and the appliance is turned back on when it makes the most sense.
This makes it possible to incorporate almost all standard appliances already in the household into the energy management system. Once activated, appliances are not interrupted; they continue operating normally, with no loss in performance quality because of the automatic control.
With premium appliances such as Miele clothes washers and dryers, which are “smart grid ready,” the Sunny Home Manager can “converse” via the network interface and start them even without an SMA radio-controlled socket.
By the way, SMA sockets are also an excellent way to hunt for hidden energy hogs. How many of us know how much current a phone charger, wireless router, or water heater consumes? An SMA radio-controlled socket, simply inserted between the load and the outlet, supplies detailed information about both how much energy the appliance uses, and when. Often, this makes it possible to detect major energy guzzlers that have gone unnoticed.
What exactly is intelligent about energy management with the Sunny Home Manager?
Unlike many other products on the market, the Sunny Home Manager is not just a threshold switch that activates a load as soon as a certain power level is available. Instead, the Sunny Home Manager calculates timetables so appliances are used at the perfect times. Calculations are based on future production, future loads, and the price of electricity in the hours ahead (even for complicated pricing models).
Using what it knows about the attached PV system and a weather forecast for its precise location, the Sunny Home Manager estimates the anticipated power generation capacity. For example, it recognizes and takes into account shade affecting the panels, even if this is not in the weather report.
The Home Manager also precisely monitors power consumption, tracking periods when loads are high or low. This enables the Home Manager to forecast typical situations and include them as it creates at timetable. For example, if mom typically cooks dinner later on Tuesdays because she has to pick up junior from sports practice, the Sunny Home Manager factors this in.
Now the Sunny Home Manager has nearly all the information it needs to generate a timetable. Take for example a washing machine with a hot water cycle that consumes 2.5 kWh of energy. Of course, the washing machine doesn’t use power uniformly throughout the cycle. The heating stage or spin cycle will demand more power than the simple agitation stage. The Sunny Home Manager also takes this into account. It can even schedule the heating stage of a normal laundry cycle to take place in the pause between the two rinse cycles of a dishwasher. Now that’s energy management.
Complex analysis functions also enable the Sunny Home Manager to deal with constantly changing power consumption. Sudden changes in weather and various household situations – vacation, a surprise party – are no problem for the Sunny Home Manager. For example, if someone fires up the electric grill to barbecue while a cake is baking in the oven, the Sunny Home Manager will make sure that the washer and dryer don’t run until the next time low-cost power is available.
Isn’t it a lot of work to shift loads around?
It does take a little adjusting to make the most of what the Sunny Home Manager can do. At night or in the morning, I load the dishwasher and washing machine and activate the automatic control for each with the click of a button. The Sunny Home Manager does the rest. When the washer is done, my wife moves the laundry to the dryer and activates its control. The whole thing is really simple, and it’s hardly any trouble once you’ve gotten used to pushing one more button after you turn on the appliances.
And here’s yet another useful feature: Our young daughter takes a nap at about the same time every day – and the Sunny Home Manager even considers this. I have programmed it not to run the washing machine during naptime, so the spin cycle doesn’t wake our little darling up
* In my household, I have tried to take full advantage of the Home Manager’s potential by using all 10 of the available SMA radio-controlled sockets. Because I have a battery storage system installed, it makes sense to manage even the smaller loads. Several days out of the year my house is almost completely self-sufficient.
Further interesting links:
I am Project Manager for our SMA Fuel Save Solution. Together with my great team I care for bringing solar energy into the most remote parts of the world
Energy management on electrical islands - in water as well as in sand