Energy management
What is intelligent energy management (HEMS), and how does it work?
Your home can already generate, store and use electricity. But who makes sure it all works together?
More Danish homes are getting solar panels, home batteries, heat pumps and electric vehicles. Each technology can be a good investment, but most have one thing in common: they come with their own app, their own settings and their own way of managing energy.
↓The solar installation knows how much electricity it produces. The battery knows how much energy it has stored. The heat pump keeps the house warm, and the EV charger makes sure the car gets electricity.
But who decides what makes the most sense for the home as a whole?
This is where intelligent energy management – also known as HEMS – comes in.
What does HEMS mean?
HEMS stands for Home Energy Management System – a system for managing energy in the home.
A HEMS brings together information about the home's energy production, energy consumption and flexible devices. Its purpose is to coordinate when electricity should be bought, stored, used and potentially sold.
A traditional energy system often responds to what is happening right now.
An intelligent energy management system also tries to account for what is likely to happen later.
For example, it can use:
- Current and upcoming electricity prices.
- Grid tariffs and other relevant costs.
- Solar production forecasts.
- The home's expected electricity consumption.
- The battery's state of charge.
- Heating and hot water requirements.
- The electric vehicle's expected charging needs.
Using this information, the system can plan energy consumption so that the different devices do not make decisions independently of one another.
The home's energy works together
Solar panels generate electricity. The home, heat pump and electric vehicle use electricity. The battery can store and supply energy, and the grid can supply or receive electricity. HEMS coordinates using available data and control capabilities.
Why has intelligent energy management become relevant?
In the past, electricity consumption in most homes was relatively straightforward. You switched appliances on when you needed them and paid for the electricity you used.
Today, the situation is different.
Many households can generate electricity, store it and move some of their consumption to other times.
At the same time, electricity prices vary throughout the day, and grid tariffs can make certain periods more expensive than others.
This creates new opportunities, but also more decisions.
Should the battery charge now or wait for tomorrow's solar production? Should the heat pump heat water while electricity is cheap? And should the car charge immediately or later at night?
Optimizing one device is not necessarily difficult. The difficult part is optimizing the entire home at once.
When every device thinks for itself
Imagine a home with solar panels, a home battery, a heat pump and an electric vehicle.
The battery's own controller might choose to charge from the grid because electricity is cheap.
At the same time, the car starts charging because its charging app has found the same inexpensive period.
The heat pump also starts to produce hot water.
Each device does what it has been programmed to do. But they have not necessarily taken one another into account.
As a result, several large consumers may start at the same time, even though spreading out consumption would make more sense overall.
A HEMS can consider these needs together and plan for them as a whole.
That does not mean everything must always run at different times. Sometimes simultaneous consumption is actually the best solution.
The point is that the decision should reflect the home's overall costs and needs, rather than each device's isolated rules.
A day with different consumption timing
- Without coordination
- With coordination
How does intelligent energy management work in practice?
An intelligent energy management system essentially does three things: understands the home, plans its energy use and carries out the plan.
1. The system learns about the home's energy use
First, the system needs a picture of how the home uses and produces energy.
How much electricity does the house normally use? When do the solar panels produce the most? How does the battery respond to charging and discharging?
Some information can be read directly from the devices. Other information can be estimated from historical measurements and improved over time.
The better the system understands the home's actual behavior, the better its basis for planning.
2. The system looks ahead
The information is then combined with upcoming electricity prices and forecasts, for example.
Imagine that electricity is cheap at night, but strong solar production is also expected the following morning.
It may be tempting to fill the battery completely overnight.
But if the battery is already full when the sun starts producing, there is less room to store the electricity generated by the home itself.
Conversely, a cloudy day may make charging from the grid more attractive.
The right choice depends on more than the current electricity price.
3. The system coordinates the devices
Once the plan has been calculated, energy management can coordinate the devices that support control.
The battery can be instructed to charge or discharge. EV charging can be placed in suitable periods. In some cases, heat production can be shifted without compromising comfort.
And if conditions change, it should be possible to recalculate the plan.
A forecast is, after all, only a forecast.
What can a HEMS control?
That depends on the system and on the data and control capabilities provided by the home's equipment.
Solar panels
Solar production cannot simply be moved to another time. But a production forecast can help plan when electricity should be used or stored.
Home battery
A battery can move energy from one time to another. Energy management can assess when it makes the most economic sense to charge, store electricity or use it.
Electric vehicle and charger
EV charging is often a large, flexible electricity demand. If the car is not needed until the next morning, charging can be planned within the available period.
Heat pump and hot water tank
In some cases, a heating system can store energy as heat. This makes it possible to shift some electricity consumption, provided temperature limits and comfort requirements are respected.
Other flexible consumers
Certain electric heaters and other controllable devices can also be included in an overall energy plan.
What matters is not how many appliances are connected, but whether the system can coordinate them meaningfully.
Can you make money by buying electricity cheaply and selling it at a higher price?
A home battery can do more than store electricity from solar panels.
When electricity is cheap, the battery can be charged. When electricity later becomes more expensive, the energy can be used at home or, in some cases, sold back to the grid.
This is called energy arbitrage. It simply means taking advantage of price differences at different times.
But there is an important difference between saving money by using the electricity yourself and making money by selling it.
Using the battery to avoid expensive electricity
Imagine that electricity is cheap at night but expensive in the late afternoon.
A home battery can charge during the inexpensive period and later supply the home's own consumption.
This avoids buying some electricity when it is most expensive.
It can provide an economic benefit even if the battery never sells a single kilowatt-hour to the grid.
Selling electricity from the battery back to the grid
If the battery and installation support export, it may also be possible to sell stored energy when the export payment is high.
But a high selling price does not necessarily mean the trade is profitable.
Among other things, you need to account for:
- The price of the electricity that was bought.
- Energy losses during charging and discharging.
- Grid tariffs, taxes and other costs.
- The actual payment received for exported electricity.
- Battery wear and any costs of additional cycles.
- Whether the energy could be more valuable if used at home later.
Upcoming solar production can also change the calculation.
If the battery is expected to fill from solar panels the next day, it may be more attractive to free up capacity in advance.
Conversely, selling the battery's energy may be a poor decision if the house soon has to buy expensive electricity for its own consumption.
Intelligent energy management is therefore not just about finding the highest selling price, but about choosing the most economical use of the energy.
The possibility of automatic purchasing and resale depends on the installation, the export agreement and the functions supported by the energy management system.
Is HEMS the same as a smart home?
Not quite.
A smart home is broadly about connecting and automating devices in the home.
These might include lights, thermostats, sensors, alarms and energy meters.
A HEMS has a more specific purpose: managing energy.
The two can, however, work very well together.
One example is Home Assistant, which can bring together information and control from many different manufacturers.
Home Assistant provides a shared technical foundation, while an energy optimization solution can use the information to calculate what makes the most sense overall.
That is also the idea behind Fluks.
Do you need to be an expert to use intelligent energy management?
That depends very much on the solution.
Some energy management systems require users to configure battery parameters, power limits, forecasts, automation rules and control strategies themselves.
That offers great flexibility, but can also make setup extensive.
And it raises an obvious question:
Why should you need to understand the energy market and your battery's technical characteristics just to help your own home use electricity more intelligently?
That is exactly the challenge Fluks was developed to address.
Fluks: energy management that learns about your home
Fluks is an intelligent energy management solution that brings together the home's energy equipment and plans how it can best work together.
Rather than asking users to enter a long list of technical details, Fluks is built on a principle of zero-config.
The system uses available measurements and observations to gradually learn the home's characteristics.
For example, this can include how the battery charges and discharges, how much energy particular devices use, and how household consumption develops.
Fluks combines this knowledge with electricity prices, forecasts and the needs the system can infer or is told about.
This allows the energy plan to adapt continually as conditions change.
Home Assistant is the first integration path to the home's devices. That means Fluks can build on existing integrations instead of being tied to a single manufacturer.
To control a device, the integration must of course provide the necessary data and control functions.
Zero-config is not just a feature in Fluks. It is a fundamental principle.
The aim is for technical complexity to live in the software – not with the homeowner.
Can intelligent energy management save money?
Yes, intelligent energy management can reduce electricity costs if the home has flexible consumption or the ability to store energy.
But the amount you can save depends on factors including:
- Differences in electricity prices and grid tariffs.
- How much electricity the household uses.
- Solar production.
- Battery capacity and energy losses.
- How flexibly EV charging and heating demand can be shifted.
- How well the energy plan matches the home's actual needs.
There is no guarantee of a particular saving.
A home with substantial flexible energy demand may have different opportunities from an apartment without a battery, electric vehicle or heat pump.
That is why a HEMS should focus not just on the cheapest electricity price, but on the overall economics of the decisions it makes.
The future of energy management is about working together
Solar panels, batteries, heat pumps and electric vehicles are becoming increasingly common.
But more intelligent devices do not automatically create an intelligent energy system.
If every device only optimizes its own task, the home can still miss out on the opportunities offered by coordination.
This is where HEMS makes a difference.
A good energy management system should do more than show what is happening. It should understand the connections, plan ahead and adapt its decisions when reality changes.
And ideally, it should do so without requiring the homeowner to become an energy professor.
You do not need to understand the energy market to get the best from your energy. Fluks does that for you.
Fluks – Your energy. Decides together.