MCBW Energy Efficiency

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The Green Garage is working with MCBW to improve the energy efficiency of it's brewing process. This will lower the ecological footprint of the business and reduce it's operating costs per barrel.

Project Goals

Three primary goals:

1) Reduce the energy per barrel (BTU/BBL) by 50% in comparison to the current energy per barrel.
2) The energy improvement projects are to have a simple payback of 5 years or less.
3) The target investment for these improvements is $50,000 (or less) above the current planned investment to increase the brewing capacity.

Secondary goals:

1) A energy efficiency project was given higher priority if it also resulted in reductions in water consumption and/or improvements in brewing quality.
2) Preservation of current assets. If an existing condition puts a current asset's life expectancy at risk then by remediating the condition we extend the life of the asset...saving the asset, money and waste.

Project Scope

In Scope

Brew Tanks

Limited to energy use in all steps of the brewing process including:

  • Heat-centric
    • Mashing and Lautering
    • Wort Boiling
  • Cooling-centric
    • Fermentation tanks
    • Bright tanks
    • Serving tanks
    • Cold storage rooms
      • Existing room in building A
      • New room in Willy's building across the street
  • Washing of tanks, bottles and kegs
  • Bottling line
  • Heat Exchangers

Out of Scope

  • Building heating and cooling
  • Water usage...except as directly tied to energy usage

Brewing Production Capacity

  • Brewing volume in for the 12 month period from November 2010 through October 2011 is 1740 BBL.
  • Future brewing capacity assumed to be 5,000 BBL per year. It is recognized that the planning target is 3,000 BBL's, however the physical capacity should be used in these calculations. If MCBW decides to brew less than physical capacity that is a separate business decision.

Estimating Current Energy Usage


  • 250 kBTU / BBL is our estimate for the current energy usage of MCBW in brewing.
    • 150 kBTU / BBL from steam
    • 100 kBTU / BBL from electricity
    • Overall, this shows that MCBW has been prudent in the use of energy for brewing, while significant opportunities for improvement still remain.
  • MCBW energy sources:
    • Detroit Thermal steam is used for all heating in the brewing process. One meter.
    • DTE electricity is used for all cooling. One meter.
  • Calculation Approach
    • Steam
      • Bottom up science-based approach resulted in an estimate of current use of steam as 157 kBTU/BBL.
      • Current meter readings for steam are not accurate.
    • Electricity
      • Starting with the total annual actual electric usage:
        • We backed out the pizza oven usage based on circuit metering (using loggers) and assumed that 10% of the total electric usage was due to non-brewing uses (e.g. building) resulting in an estimated actual of 100 kBTU/BBL of electrical usage.
        • Used circuit metering (loggers) to determine that the cold storage room in building A accounts for 42 kBTU/BBL of the electricity load.
        • Assumed the remaining 58 kBTU/BBL was due to other parts of the brewing process...mainly the fermentation and conditioning.
  • We estimated that MCBW brewing energy usage is 60% Steam (heating) and 40% Electrical (cooling). This ratio is supported by other studies of breweries large and small. See Research below.

Electricity Key Details

  • We estimate MCBW annual electricity usage for brewing over the 2010 full year and 2011 through October. The result was 100 kBTU/BBL
  • This was calculated by:
    • Over the 22 month period, 2010 + 2011 Partial, Total MCBW Electrical Usage was = 246,716 kWh (from meter) or 11,214 kWh / mo.
    • LESS:
      • 5,967 kWh / mo for the Pizza oven. This was confirmed by:
        • Actually measured it for a 4 day period. 6,100 kWh/mo was measured.
        • Read the wattage rating of 15.6 kW on the name plate and assumed it was on 75% of the time from 9am to 2am.
      • 1,121 kWh / mo for the building lighting, computers, fan, etc. which was assumed to be 10% of the total.
    • The 100 kBTU/BBL result is calculated in detail in the "MCBW Energy Efficiency Study Workbook" Google Doc on tab "MCBW Energy Usage"

Steam Key Details

  • Science-based bottom up process-based calculation resulted in 157 kBTU / BBL of heat
  • Because of irregularities with the current steam meter we used steam calculations based on thermal calculations. Differences can be traced back to the new steam meter installation in April 2010.

Estimating Future Energy Usage


  • We estimate a 51% reduction in BTU/BBL by completing the five projects below. This would result in future estimated energy usage of:
    • 123 kBTU/BBL for total future energy usage of MCBW in brewing.
      • 73 kBTU / BBL from steam; a 51% reduction
      • 50 kBTU / BBL from electricity; a 50% reduction
  • Total Estimated Cost Savings
    • One Year: $ 20,000
    • Five Year: $100,000
  • Key assumptions
    • MCBW energy sources:
      • Steam:
        • City steam will be used as external source for all heating in the brewing process.
        • One meter.
        • Average Five Year Rate: $21.26/Mlb.
      • Electricity
        • DTE electricity will be used for all cooling.
        • One meter.
        • Average Five Year Rate: $0.14/kWh
      • Brewing Production
        • Assume 5,000 BBL production
  • Calculation details can be found on the "Management Summary" tab in the Google Doc "MCBW Energy Efficiency Study Workbook"

Electricity Key Details

  • Energy reduction for cold storage room insulation is calculated on existing cold room only at current brewery output - 1740 BBL/Yr. It is assumed that doubling the cold storage room area and basically doubling the brewery output would cancel each other out and maintain the same kBTU per Barrel. Thus, we simplified the calculation and used current cold room at current beer output with improved insulation.

Steam Key Details

  • Recovered waste heat from cooling will offset steam use to heat washing water, since wash water use is estimated to be very high, and the hot liquor tank provides almost all hot water needed for starting the brew process.

Energy Efficiency Projects

Project 1: Insulated Hot Liquor Tank

  • Description: 30 BBL existing uninsulated tank, insulated to R16.5
  • Energy Type: Steam
  • Energy Reduction: 26 kBTU/BBL; 10% of Total
  • Cost Savings: One Year = $3,000; Five Year = $15,000
  • Project Cost: $4,500 (including whirlpool insulation)
  • Payback Period: 1.5 years; Less than Five: YES
  • More detail: MCBW Project Summaries (A Google Doc)

Project 2: Insulate Cold Storage Rooms

  • Description: Improve insulation on 20x10x10 ft existing cold storage room to 20 R value, and build new cold storage room to 20 R value. The existing room will be upgraded fully in about a year to accommodate planning for future needs for the room. In the interim, the ceiling insulation will be improved to about R30.
  • Energy Type: Electricity
  • Energy Reduction: 34 kBTU/BBL; 13% of Total
  • Cost Savings: One Year = $7,500; Five Year = $37,500
  • Project Cost: $1,200 (Cost is to insulate ceiling only in existing room; Full costs of re-insulating existing room and building new room are TBD)
  • Payback Period: The entire final project will include energy efficiency improvements as well as brewery operations improvements. Only the energy related costs should be applied here.
  • More detail: MCBW Project Summaries (A Google Doc)

Project 3 New Chiller

3A - High Efficiency Chiller

  • Description: New Chiller with two 5 hp compressors to meet all MCBW brewing related chilling needs at the existing site. The existing chiller will be moved to the Willy's cold storage site.
  • Energy Type: Electricity
  • Energy Reduction: 17 kBTU/BBL; 7% of Total
  • Cost Savings: One Year = $3,700; Five Year = $18,500 (Note: Savings from the variable speed circulating pump are not included since they are system dependent.)
  • Project Cost: $4,800 = $1,800 for a Variable Speed Circulation Pump + $3,000 portion of the new chiller costs (for glycol tanks). (Note: The $19,000 ($22,000 less $3,000) for the new chiller + $5,000 for integration costs are not included, because the chiller was needed to meet the expanded capacity. Larger glycol holding tanks would be the only costs that could be considered due to high efficiency requirements.)
  • Payback Period: 1.3 Years: Less than Five: YES
  • More detail: MCBW Project Summaries (A Google Doc)

3B - Recover Waste Heat from Cooling

  • Description: Use an existing 20 BBL Brite Tank and convert it to tepid water reservoir for capturing heat from cooling process. Connect Chiller and Tank with new plumbing and heat exchanger to transfer heat from glycol loop (chiller side) to city water (collecting tank side). Assumes Project 3A: New Chiller is also implemented.
  • Energy Type: Steam
  • Energy Reduction: 46 kBTU/BBL; 19% of Total
  • Cost Savings: One Year = $5,000; Five Year = $25,000
  • Project Cost: $9,000
  • Payback Period: 1.7 years; Less than Five: YES
  • More detail: MCBW Project Summaries (A Google Doc)

Project 4: Recover Heat from Steam Condensate

  • Description: Capture steam condensate into a vessel, and pump it through a heat exchanger to transfer heat to cold city water
  • Energy Type: Steam
  • Energy Reduction: 4 kBTU/BBL; 2% of Total
  • Cost Savings: One Year = $500; Five Year = $2,500
  • Project Cost: $4,000
  • Payback Period: 8 years; Less than Five: NO
    • This project is still recommended since a key consideration is to reduce the damage to the PVC drain plumbing.
    • Cost avoidance for replacing PVC line connect to sewer 12 feet underground is likely in the $15,000 - $20,000 range and quite possibly higher.
  • More detail: MCBW Project Summaries (A Google Doc)

Project 5: Mini-Projects

  • Description: Insulate Pipes: Steam, Glycol, Beer, etc.; Check design and operation of Heat Exchangers (3): Steam (1), and Wort (2)
  • Energy Type: Steam and Electricity
  • Energy Reduction: Difficult to Project kBTU/BBL
  • Cost Savings: Difficult to Project
  • Project Cost: $Minimal
  • Payback Period: Likely less than 5. Essentially, this is Preventative Maintenance
  • More detail: MCBW Project Summaries (A Google Doc)

Supporting Analysis

MCBW Energy Efficiency Study Workbook

This Google doc spreadsheet is the primary analysis document, and can be found here: MCBW Energy Efficiency Study Workbook

A description of the tabs on that spreadsheet is below:

  • Management Summary: This sheet is a summary of all the energy savings and costs savings for the whole project.
  • Calculated Energy Basis:
    • This sheet summarizes the current estimate of energy usage, and shows the energy savings potential of 10 projects that were investigated.
    • The calculated energy basis shows energy demand as calculated from a scientific and process based analysis. We found that the steam usage calculated was very reasonable compared to other benchmarks, but the electricity usage was not. Therefore, the electricity energy used per barrel was calculated using the monthly electricity use data from DTE, and the measured actual data from data loggers attached to the pizza oven and the two chillers. This was calculated as 100 kBTU/BBL.
  • MCBW Energy Usage: This sheet shows a summary of energy usage from data obtained from DTE and Detroit Thermal for the periods 2010 and 2011.
  • Strategy: This sheet lays out the strategy used for the project, and is as follows:
    • Reducing Primary Demand: This was the first approach used to reduce the energy needs of the system. The analogy here is for a building - you can apply geothermal to a typical building, and it is more efficient than your typical heating and air conditioning systems, maybe requiring 30% less energy. However that is an efficiency strategy. Insulating a building envelope can cut 90% of the energy demand, and this is better than the 30% reduction from geothermal. Insulating is a reduce demand strategy. This same thought process was applied to the brewing process - How can we reduce the energy required by the system.
    • Reduce Primary Waste: This was the second approach utilized, and aims to make the best use of the energy that is already in the system, and see that none escapes without being properly utilized. Since the brewing process requires forcing temperatures first up and then down, there was found to be good opportunity to recapture heat energy and use it back in the process.
    • Supply with Renewable Non-Carbon: After energy needs are reduced, waste is eliminated and existing energy is reused where possible, energy must be put into the system. This strategy aims to supply that energy with renewable energy that is not carbon based, ie solar hot water, wind, pv, etc.
    • Supply with Renewable Carbon: The next most desirable source of energy is renwable, but based on carbon, ie biomass.
    • Supply with Non-Renewable Carbon: After renewable sources, any remaining energy needs will be supplied by non-renewable carbon based, such as natural gas, coal fired electricity, etc. It must be noted that if primary demand is substantially reduced (90% in the above building example), it may make the most sense to simply supply the remaining 10% with existing non-renewable sources.
  • Processes - Current: This sheet represents the brewing process as described by MCBW personnel, and holds calculations of material and energy flows that leads the total energy used calculations in the Calculated Energy Basis sheet. Also, theses numbers are used heavily in the calculations for Strategy BTU Calculations
  • Strategy BTU Calculations: This sheet holds the calculations for all energy savings projects analyzed.
  • Processes - EE: This is the beginning of a future energy efficient process sheet, and was only completed as far as necessary for the work needed for the project. It is not finished, but represents an asset to help build upon for future work.
  • Ypsi Energy Usage: This sheet summarizes energy use at the Corner Brewery according to the UM Green Brewery Project
  • LBNL Energy Usage: This sheet summarizes energy uses in larger breweries generally, according to a report: "Energy Efficiency Improvement and Cost Saving Opportunities for Breweries" from Lawrence Berkeley National Lab through the Department of Energy's Energy Star program.
  • Wort HX Calcs: This sheet holds calculations showing the relationship of water output temp to wort temps and volumes, and water inlet temp and volume. This is to help guide analysis and measurement of water usage since that is the one element of that system is not currently monitored directly.
  • Chiller Heat Recapture Sizing: This sheet holds calculations to help guide sizing and energy usage planning for the tepid water storage tank which holds heated water from the chiller energy recapture system.

MCBW Energy Usage Analysis.xls

This workbook contains utility data for MCBW for Electricity (DTE) and Steam (Detroit Thermal) for the years 2010 and 2011, and some analysis on average usage per BBL. MCBW Energy Usage Analysis

MCBW Pizza Oven Energy Data.xls

This workbook contains actual usage data for the pizza oven electricity usage for 4 days from 12/13/2011 through 12/17/2011, and also contains analysis calculating monthly pizza oven energy usage. MCBW Pizza Oven Energy Data

MCBW Cold Room Chiller Energy Data.xls

This workbook contains actual usage data for the Cold Room Chiller electricity usage for 4 days from 12/13/2011 through 12/17/2011, and also contains analysis calculating monthly Cold Room Chiller energy usage. MCBW Cold Room Chiller Energy Data

MCBW Process Chiller Energy Data.xls

This workbook contains actual usage data for the Process Chiller electricity usage for 2 days from 12/7/2011 through 12/9/2011. Since the chiller did not run much during this period, this data was not used to calculate energy uses. Data from other sources (monthly DTE utility bills, actual pizza oven energy usage data and actual cold room chiller energy usage data) were used to estimate process chiller energy use. MCBW Process Chiller Energy Data

Next Steps

1. Integrated Modeling for Performance Optimization

  • Process flow...BBL's production
  • Staffing estimates...feed scheduling
  • Raw material ordering...feed inventory mgmt
  • Space estimates ... feed material handling
  • Energy Estimates ... feed setup scheduling
  • Financial / Profitability estimates

2. Develop Sequence of Operations and Requirements

3. Send Estimates into chiller companies for sizing and bids.

4. Professionally developed design:

  • Pumps,valves, piping, measurement devices
  • Exchangers
    • Have all three exchangers inspected and sizing re-estimated using new requirements.
    • Confirm data from wort doesn't work with current data.
  • Chiller and tank integration
  • Integrate existing chiller into new cold room design
  • Develop 3D CAD Model of mechanical systems

5. Design for the Cold Storage Room

  • Allows finalization of costs for insulation
  • Integrate existing chiller into design

6. Organizational Capability (that supports the scale of the operations)

  • Procedures and Training
  • Measurement and Reporting
  • Continuous Improvement


Project Information

Project Team To Do's

  • Review/update Project Scope section (Nic)