Closing the loop
By interconnecting utilities and services like electricity, water and district heating, cities can unleash new powers of optimization that reduce operating costs, energy use and pollution.
For instance, ABB has developed solutions that coordinate the operations of municipal water/wastewater, district heating/cooling and power systems, enabling them to operate as a unified system within a closed loop system.
Here's how it works.
The many energy-hungry pumps in a water treatment plant and a district heating network do not need to run all around the clock. Even though the plant and network operate non-stop, the pumps can be scheduled to run when electricity prices are lowest, without risk of shortfall.
Typically, the combined heat and power plant that produces the heat, considers the electric power production as a by-product, which it sells without taking into account price shifts and market volatility. By optimizing production to meet market needs, it could maximize revenues by delivering power to the market at peak periods. Remember: the plant is powering the city’s water and district heating pumps at off-peak times and has excess power to sell when demand is highest.
Enabling this solution are advanced ABB optimization algorithms that adjust network pressure and temperature, control pumps optimally, forecast heat and power requirements, and schedule production in line with demand and market prices.
Smart city solutions for Sweden
Earlier this year, ABB was selected by Swedish multi-utility Mälarenergi to develop smart city solutions for Västerås, Sweden’s fifth largest urban area.
Mälarenergi operates hydropower plants, the local power grid, a waste-to-energy plant, heating and cooling networks, water and wastewater treatment plants, a water distribution network and a fiber-optic network for the city’s 150,000 residents and businesses.
A key objective of the project is to integrate the control rooms of the many automation systems that manage the city’s utilities and services into one unified operating environment. Another is to reduce the city’s water losses in the distribution network by 20 percent and cut energy use by the district heating network.
Unified energy and water management
In Germany, one of the country’s most progressive smart cities is Trier. There, the local municipality Stadtwerke Trier supplies electricity, gas, drinking water and district heating. It also treats wastewater and is responsible for the public transportation system.
ABB has already developed a smart energy management system for the city’s diverse range of generation sources - wind power, hydropower, solar photovoltaic, biomass, combined heat and power (both large-scale conventional and micro CHP), as well as for battery storage, heat pumps, electric vehicle chargers and industrial loads.
The solution optimizes production, balances it with consumption and is connected to weather and load forecasting tools. It has the scalability and flexibility to seamlessly integrate new generation units, storage devices, vehicle charging stations and other loads without disruption to operations.
In a new project (Interreg VA EnergiewabenGR), ABB is working with Trier to connect the city to three other municipalities in France, Belgium and Luxembourg, each of which operates its own power pool of diverse types of generation and storage. The solution will enable the pools to compensate for fluctuations in renewable energy by exchanging power with each other and using storage capacity intelligently. This in turn will maximizes their use of renewables and minimize their dependency on the national grids.
Now, Trier and ABB are connecting the waste water plant, the water network, on-site PV generation and the CHP plant in a separate power pool to reduce operating costs. This is another instance of how the coordination of utilities and services – in line with the city’s vision, strategy and targets - creates value for the municipality and its citizens.