Low-Cost Energy Management and Control System for Small to Medium Commercial Buildings
Energy Management and Control System for Small to Medium Commercial Buildings: Low-Cost vs. None
Affordable and cost-effective monitoring and controls solutions for small- to medium-sized commercial buildings.
Item ID: 347
Multiple Energy Systems--Energy Management
Technical Advisory Group: 2011 Energy Management TAG (#4)
Average TAG Rating: 3.2 out of 5
TAG Ranking Date: 09/29/2011
A low-cost energy management control system (EMCS) for small- (1,000 sf to 5,000 sf) to medium-sized (5,000 sf to 50,000 sf) commercial buildings can provide significant energy and cost savings. A number of vendors can provide cost-effective solutions to support this activity. However, there is lack of packaged solutions. In addition, customers are not fully aware of the benefits of using centralized building controls. A market transformation initiative targeted at developing a packaged solution and educating building owners about its benefits is needed.
California promotes "Advanced Automation" for businesses that typically have 200 kW of electric load or over 20,000 square feet of space(Xenergy and Nextant, 2002). They differentiate between "notification-based", "analysis-based", and "response" systems with two way communications. Prior to selecting an advanced automation package, they suggest evaluating how your building is currently controlled, assessing the optimum level of automation for a facility, and then capturing of benefits through employing strategies that reduce energy costs through more control over facilities and equipment. They note that energy savings are greater for those with larger energy use and suggest optimizing programming of existing energy management systems, increasing the amount of monitoring or addition of control points for existing systems, or installation of a new energy management and/or energy information system (or a combined system). Increased building monitoring and control (automation) may save between 5% and 15% of overall building energy consumption.
The Siemens EcoView wireless energy management system offers electrical consumption, lighting, and HVAC monitoring and controls and can reduce consumption by as much as 18%, delivering a simple payback of less than 2 years. As of early 2013, several manufacturers of smart residential thermostats are becoming more capable of the kind of monitoring and control required by small commercial customers, and are providing software that allows access to multiple thermostats and other linked wireless devices to be controlled from a single web portal that can be accessed through a PC or mobile devices. For instance, the Ecobee smart thermostat is being adapted for small business real time energy monitoring and management applications. The Ecobee can wirelessly communicate with the utility smart meter and up to 30 smart plugs or smart strips.
BC Hydro conducted field tests of an Ecobee "system" in a small cabinet shop and documented an electrical energy savings of 45,000 kWh per year (55% of initial process energy use) mainly through turning off protable electric space heaters. The simple payback was 0.7 years when both natural gas and electrical energy savings were considered and 1.8 years based upon electrical savings alone. BC Hydro selected the Ecobee as it is capable of being adapted to a broad range of customers.
Baseline Description: Status Quo
Baseline Energy Use: 17.3 kWh per year per square foot
For a retrofit application, the baseline is the status quo. For control at the plug level, the baseline varies tremendously due to what is plugged in to a wall outlet and the reliance on users to turn equipment on and off.
For medium sized buildings, the Cadmus "Northwest Commercial Building Stock Assessment" shows an average commercial building electrical energy use index (EUI) of 17.3 kWh/sf/year. It is assumed that the EMCS will control both heating and cooling plus indoor and outdoor lighting, which represents the bulk of the total building energy use.
Manufacturer's Energy Savings Claims:
"Typical" Savings: 10%
Savings Range: From 5% to 18%
How much a facility will save from an enhanced automation upgrade depends upon the current level of control and which upgrades might be appropriate for a given facility. Most systems control HVAC and lighting, and many different control strategies may be employed. TXU Energy estimates that building automation systems save between 5% and 15% of overall building energy consumption. They note that older or poorly maintained buildings can benefit greatly, sometimes yielding savings of over 30%(TXU Energy, 2013).
Best Estimate of Energy Savings:
"Typical" Savings: 10%
Low and High Energy Savings: 10% to 55%
Energy Savings Reliability: 3 - Limited Assessment
BC Hydro recently completed a demonstration of the Ecobee smart thermostat and the ThinkEco Modlet smart plug. These products can be used in residential and small business settings and wirelessly connect with a users PC or mobile device. The Ecobee smart thermostats cost $411 per unit and were used to control baseboard heating, an overhead radiant-tube heating systsm, and space heating in a shared lunchroom.
The Ecobee thermostats resulted in a savings of 55%, valued at $3,300 per year for electricity and natural gas combined. The simple payback was only 0.7 year. The Modlets connect to a web portal that allows the user to view energy consumption in real time and to either schedule or manually turn devices and appliances on and off. This simple technology, that plugs directly into wall outlets, allows users to monitor energy use, prevent vampire power drains, and generally reduce the overall costs to run electronic devices. Cost is about $350 for a "starter kit" consisting of 5 smart plugs.
The small cabinet shop used two starter kits and produced a plug load savings of 2,800 kWh/year, equivalent to a 44% reduction in plug load valued at $250 per year. Almost all of the Modlet savings was obtained from control of five under-desk space heaters. Mechanical tools tended to have on/off switches, and phantom loads were often so low (7 W) that the annual savings of 42 kWh ($3.69) didn't justify Modlet use. BC Hydro recommends that Smart Plugs only be used for high plug load devices such as space heaters or window-mounted air conditioners that draw several hundred to 1,000 Watts.BC Hydro conducted field tests of the ThinkEco Modlet and achieved energy savings of 44% during the winter period---equivalent to 280 kWh per smart plug deployed. Savings dropped to 14% in the summer. These savings might not be typical as, in this cabinet shop environment, protable space heaters were plugged into many of the wall outlets. These units had been historically left on at night, so energy savings from space heater control were impressive.
Energy Use of Emerging Technology:
15.6 kWh per square foot per year
Energy Use of an Emerging Technology is based upon the following algorithm.
Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))
This number is representative of an Energy Star database 40,000 ft-2 all electric building located in Western WA. An energy savings of 10% is subtracted from the baseline building energy use to reflect energy use with the advanced control technology deployed.
Potential number of units replaced by this technology:
The Cadmus study indicates that small and mid-sized buildings make up about 52% of the regional commercial building floor space of 2,704 million sf (Page 2 and Figure 9, page 19). (2,704 x 0.52 = 1,400 million sf). ( NEEA, 12/21/2009) The report also notes that 37% of the buildings already have energy management and control systems (EMCS) with another 33% of commercial buildings already using programmable thermostats (From Tables C-DC1 and C-DC2). The target for this low-cost energy management and control systems technology is the 30% of commercial building space that is operating absent controls. The "controllable" square footage is thus 0.3 x 1,400 million sf = 420,000,000 sf.
Regional Technical Potential:
0.73 TWh per year
Regional Technical Potential of an Emerging Technology is calculated as follows:
Baseline Energy Use * Estimate of Energy Savings (either Typical savings OR the high range of savings) * Technical Potential (potential number of units replaced by the Emerging Technology)
Installed first cost per: square foot
Emerging Technology Unit Cost (Equipment Only): $0.09
Emerging Technology Installation Cost (Labor, Disposal, Etc.): $0.00
Baseline Technology Unit Cost (Equipment Only): $0.00
The cost will vary depending on the extent of monitoring required, but should be within a predictable range based on building size. The installed cost and energy savings will both increase with building size; the larger the building, the greater the savings. Installation will be more costly in retrofits than in new construction. For simple, single zone packaged systems, the cost should be in the range of $500 to $1,500. For more complicated system the cost would increase by about $200-$400 per zone. It will be assumed that our baseline mid-sized 40,000 ft-2 building consists of four floors with ten zones. Total installed equipment cost is about $1,000 plus 9 x $300 = $3,700 installed (or $0.0925/sf).
For energy management at the plug level, BC Hydro conducted a study under which 10 ThinkEco Modlets were installed for plug load management. Purchase and shipping costs were $709.99 for the ten units. Actual installation was easy (taking one hour for the ten Modlets) as the devices plug into standard wall outlets but have circuitry that monitors power consumption as well as executes schedules for turning each socket on and off. The Modlets connected with a local computer via a USB Key and a Zigbee mesh-network. For each Modlet, the user must enter the name of the connected appliances with the type of appliance selected from a drop down list. Connection configuration was problematic as modlets tended to not stay connected all of the time. About 14 hours of time was required to debug and connect the ten Modlets. Once the system was up and running, the Modlet scheduling worked as advertised. BC Hydro concluded that it takes a devoted energy-saver to persevere with this product. (Note: the installation costs shown above represent 1.4 hours of time at $40/hour).
Simple payback, new construction (years): 0.6
Simple payback, retrofit (years): 0.6
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.
In most cases, with reasonable utility rates (more than $0.08/kWh), a three-year pay back is reasonable.
An energy management and control system (EMCS), sometimes also referred to as building automation system, enables monitoring and control of the energy use in a building to help conserve energy. For small- to medium-sized commercial buildings, solutions must be low-cost and easy to implement.
Many small- and medium-sized buildings lack centralized controls of most major end-uses. For example, the heating, ventilation and air conditioning and lighting systems are not scheduled to be off during unoccupied nights, holidays and weekends. Turning systems off when the building is not occupied will save significant energy. In addition, other systems like exhaust fans run almost 24x7. These systems also can be turned off during unoccupied hours. EMCS also can be used to provide optimal start and stop capabilities and reset zone temperatures. EMCS also provide an easy way to monitor various systems that are being controlled.
A number of vendors provide components necessary to develop a central control system. However, the lack of packaged solutions and lack of awareness of benefits from use of such controls have hindered wider adoption.
Many small- and medium-sized buildings lack centralized controls of most major end-uses. For example, the heating, ventilation and air conditioning and lighting systems are not scheduled to be off during unoccupied nights, holidays and weekends.
BC Hydro conducted field tests of an Ecobee "system" in a small business and documented an electrical energy savings of 45,000 kWh per year (55% of initial system use). The simple payback was 0.7 years when both natural gas and electrical energy savings were considered and 1.8 years based upon electrical savings alone. BC Hydro selected the Ecobee as it is capable of being adapted to a broad range of customers. Econnect is a new programmable thermostat for residential use, with a built-in EMS. BC Hydro will run a field test. This is a competitor for the Ecobee EMS.
Verisae has a new Apollo SaaS (software as a service) pilot in 1,300 grocery stores in the UK to integrate and control all electricity loads. If successful, the project will expand to more of Verisae's 60+ clients in grocery and other retail chains.
"Advanced Telemetry provides HVAC controls for fast food chains and other franchise-based building portfolios, where replicating similar control templates across hundreds of similar building layouts makes sense." (GreenTechMedia link below)
Kite & Lightning
Kite & Lightning is a startup in Seattle with a "Unity" EMS controller for restaurants. Prices start below $10,000 for a three-year warranty, and payback is often within 18 months. The controller tracks various sensors and HVAC components via wireless network, and may include lighting controls. Energy Trust of Oregon is starting a pilot of 20+ installations. The goal is to prove 15% energy savings. Puget Sound Energy showed 9% savings in a pilot of a previous product.
AirAdvice.com offers benchmarking, diagnostic software, and BuildingAdvice™ wireless monitors to measure temperature, humidity, carbon dioxide and lighting. MacDonald-Miller Facility Solutions offers this system for monitoring building performance.
The BC Hydro cabinet shop obtained energy savings while improving comfort as the building was pre-heated 30 minutes before the workers arrived.
End User Drawbacks:
Although a number of control vendors provide products that can be used in small- and medium-sized buildings, the lack of packaged cost-effective solutions makes it difficult for building owners to adopt EMCSs. In addition, the buildings market is fragmented and split incentives (where the building’s owner, not the tenant, gets the incentive) compound this difficulty.
According to Commercial Building Energy Consumption Survey data published by the U.S. Energy Information Administration, about 10% of the buildings representing 30% to 40% of floor space use EMCSs. It is difficult to say how many of these buildings are less than 50,000 square feet, but the data indicates that small- and medium-sized buildings typical do not have EMCS.
Unless operation is foolproof, savings from EMCS may not be realized if controls are manually over-ridden.
For this technology to be widely adopted, a market transformation effort is needed that will create packaged EMCS solutions and educated building owners and tenants on the benefits of using EMCS. To promote any energy efficiency measures in small- and medium-sized commercial buildings, a utility needs an effective program, such as the longstanding program enacted by the Sacramento Municipal Utility District. Without such a program, the adoption of EMCS will not advance.
Operations and Maintenance Costs:
No information available.
Like most control products, EMCS will last for a number of years before they need to be upgraded. However, some systems may be better than others at maintaining energy savings over a 5- to 10-year timeframe, despite changes in maintenance personnel and upgrades in electronic products.
EMCS used in large buildings may be too expensive. Some owners of small buildings might adopt simpler packaged solutions like the home energy management systems.
Reference and Citations:
Xenergy and Nextant,
Enhanced Automation: Business Case Guidebook
California Energy Commission
Nextant and Xenergy,
Enhanced Automation: Technical Options Guidebook
California Energy Commission
Building Automation Systems: Business Energy Efficiency
TXU Energy Retail Company
Small- and Medium-Sized Commercial Building Monitoring and Controls Needs: A Scoping Study
Pacific Northwest National Laboratory
The Automated Energy-Saving Grocery Store Goes Live
Bridging the Small Commercial Efficiency Gap: SCL Elements Raises $2.15M
BC Hydro ,
New SMB carbon management software options
PowerMand Pioneers New Approach to Demand Response
Northwest Commercial Building Stock Assessment (CBSA): Final Report
Prepared by the CADMUS Group for the Northwest Energy Efficiency Alliance