6 April – Case study: Energy management software company

Perth Council House

BuildingIQ claims it has reduced energy costs by up to 30 per cent daily in total base building energy in a trial during event days in the historic Perth Council House

The company said it achieved an overall 12 per cent reduction during the trial and optimised controls in what it claimed was the world’s first deployment of a system that uses predictive energy optimisation for demand response events

In the US where the company also operates, demand response programs are used by utilities to reduce peak load energy consumption in commercial buildings, which consumes 20 per cent of energy in the US.

Energy challenge

Perth Council House contains an outdated and limited control system and mechanical plant. The last substantial plant and controls upgrade was in 1999. Despite this, it was crucial for the facility to reduce overall power demand as well as reduce peak loads in response to external parameters such as utility company – created demand response programs.

Working with Western Power and the City of Perth, Building IQ’s application DRIQ, successfully married “inside the meter” energy management with “outside the meter” smart grid applications,

Demand management manager at Western Power, Peter Martino, said: “Reducing peak loads during critical demand days is an important focus of Western Power, and being able to dynamically manage this while considering tenant comfort is a key to getting building owners to participate in demand response management programs.”

BuildingIQ claims its DRiQ is the first system that can predict and then dynamically manage energy through a demand response or DR event, with a unique ability to reduce energy usage while minimising tenant impact.

The system gathers the building’s unique thermal characteristics and capacity to shed loads, pre-plans the energy use in the building based on weather forecasts and the DR parameters, and then continuously shapes the energy use in the building to optimise cost, emissions and occupant comfort.

Jevan Fox, cleantech analyst for Pike Research, said in a media statement from BuldingIQ: “Demand response will ultimately become an application within a broader energy management platform. The ability to manage demand response signals and events while optimising a building to make it increasingly energy efficient will be vital for commercial end-users”.

BuildingIQ chief executive Michael Zimmerman said the company’s ability to learn a building’s operational capacity and then both control and optimise energy puts it in a unique position when it comes to demand response.

Situation summary

Utilities created DR programs to provide financial incentives for building owners to reduce energy consumption during peak periods. Utilities pay this out because the alternative is to build more power plants, which will ultimately cost the industry billions.

• Peak electricity use rate in late 2009 was $0.22 kWh.
• Typical annual energy use was 2.8 million kWh.
• Building control system: Siemens system 600.
• Last substantial plant/ controls upgrade: 1999.
• Thermal plant: One high load large chiller and one small, low load chiller. No hot water plant. Heating by local VAV reheats, electric.
• Air handling: 2 AHU’s per floor covering north and south zones.
• VAV’s controlled independently of the BMS.
• BuildingIQ Communications: Tridium JACE with CSI3 System600 driver.

Solution summary
BuildingIQ works by interfacing to the existing building management system using industry standard interfaces and leveraging existing investments in the BMS and mechanical plant.
It incorporates existing building data, outside data such as weather forecasts, energy tariffs and demand response signals, and proprietary algorithms to continuously optimise energy use for the building.
This is done automatically once the system is configured – no new sensors or building data is required. Implementation of BuildingIQ at the council house began in early 2010. Sub-metering and BMS interface work concluded in early March and the company began creating the energy model which was deployed across the whole building two months later.
The system ran continuously through the beginning of August, optimising the HVAC energy use through its control of the BMS and implementing a mix of strategies which reduced energy cost and emissions while maintaining tenant comfort.
During late July and early August, the stakeholders agreed on a plan to optimise energy use while incorporating a number of demand response parameters into the system settings.
In summary, the trial consisted of the following:
• DRIQ was running on a continuous, automated basis in the building;
• The DR event parameters were entered into the DRIQ system the day before the event and incorporated into the system’s predictive modelling for the DR event day;
• DR parameters trialled included peak day pricing, maximum demand caps and specific kW load shedding during typical peak hours in the afternoon or across the whole day;
• On the day of the event, the system managed energy use in the building throughout the day, minimising energy use during the stated event periods to satisfy the DR parameters;
• Tenant comfort was used as a key input into the optimisation, and was maintained throughout DR events. Energy use, temperatures and other building operations were reported on a real-time basis. The BuildingIQ system automatically, continuously, and in real time, manages HVAC settings throughout the day, updating both the commands and the building model based on any changes to conditions

Energy efficiency and optimisation results

The trial provided up to 30 per cent daily reductions in total base building energy, and an overall 12 per cent reduction during the trial using adaptive comfort techniques and optimised controls.

The significant savings were achieved despite the lack of a modern BMS and limited HVAC plant capabilities. These savings would represent an annual energy savings of 250,000 kWh and economic savings of about $55,000 or over three times the annual cost of a BuildingIQ subscription.

Demand response results

Demand reduction of between 15-30 per cent during moderate ambient conditions was shown. Warmer ambient conditions may result in higher demand response results however these were not tested due to the timing of the trial.

A 30 per cent demand reduction during the summer months where electrical demand reaches 800kW represents a reduction of 240kW or 26.02W/ square metres of net leasable area.

The potential value of this to the customer based on $176 KVA would be approximately $44,000. The trial demonstrated significant energy savings without adverse effects on tenant comfort. Maximum internal average temperature throughout the trial was typically in the range 24 to 25 degrees C.