Generating Electricity with Your Steam System: Keys to Long Term Savings May 19th, 2010Industrial Energy Technology Conference

Bill Bullock / Andrew Downing Turbosteam

How Most Power Is Generated

Generating Power With Your Steam System

RewardsRisksCompletion Risk Installation Done CorrectlyPerformance Risk Turbine Maintains Performance Over Economic LifeOperating Risk Turbine Maintenance

Electricity SavingsLower EmissionsImproved Operating Characteristics (Power Factor, Reliability)Releases electrical infrastructure capacity

Quantifying the OpportunityThere is a Pressure Reducing Valve (PRV) in placeThere is an opportunity or need to install new boilersThere is a desire to increase energy efficiency

Design ConsiderationsPressure and temperature conditions factoring in losses from steam piping designDesign the turbine to what the pressure will be at inlet, not what it leaves the boiler 10 psig difference at inlet can mean $30,000 or more a year in electric savingsMinimize distance from high pressure header to the inlet of turbine

Design ConsiderationsVerify that you have dry and saturated steam. Moisture in steam can destroy your investment98% quality steam can impact power output by 10% costing you thousands in savings and tens of thousands in repairsWater chemistry is vital to the protection against corrosion

Design ConsiderationsInstall a reliably accurate steam flow meter at the proposed tie in for the steam turbine. Measure your annual steam flow.Measure the pressure and temperature at location, dont assume anythingChose the low cost, best impact equipmentRecorded Steam flow for 8,760 hours to get an accurate historical trendActual steam passing through PRV, not out of boilerUse reliable pressure and temperature transmitters such as Spirax Sarco or Rosemount

Selecting Steam TurbineThere is no universal optimum: depends upon capital cost, system operating profiles, energy rates and financial objectives.Use a systematic approach to turbine sizing to provide the optimal economic solutionSteam Load5,00015,00020,00025,000500100015002000250030003500400015 minute incrementslbs/hrDesign for peak?Max kW, penalized on turndownDesign for baseload?Max capital utilizationHigh $/kWDesign for max annual kWh?10,000

Selecting Steam TurbineChoose a turbine that is going to give you optimal turn down efficiencyMatch your annual steam flow to the window of operationUnderstand what happens below and above your turbines performance curveInstalling automatic handvalves are recommended for steam flows that vary hourly or even daily

Determine your SavingsPerform an analysis of a before and after based on your historical steam flow

Case Study Delmonte The Del Monte Foods plant is a former tomato processing plant that currently packages fruit. The system consisted of two separate single stage turbines coupled to a dual shafted induction motorSteam flow demand changed based on process requirements. This option gave the lowest cost, highest turn down efficiency.Winter steam flow falls off significantly and summer steam flow increases as the harvest season approaches

Case Study Delmonte Turbine Designs

First turbine designed for a smaller inlet flow to capture more low end steamSecond turbine designed for a higher steam flow to maximize kWh productionBoth turbines couple to a single generator

Case Study Delmonte Snap shot of savings Calculations

First look at steam flows shows a generation of 2,459,664 kWh Customer did not have boiler installed yet, this was part of an expansion. Steam flows were assumed based on historical data from previous years.

Case Study Delmonte Environmental impact of onsite generation(Based on EPA eGRID 2007 Data)

By reducing their purchase of electricity by 2,500 MWh per year, this project reduces :NOx by 552 lbs annuallySO2 by 340 lbs annuallyCO2 by 612 tons annually This is environmentally equivalent to the annual CO2 released by approximately 146 cars annually

Case Study Delmonte Keys to their success

They realized they had a potential to generate on site electricity and reduce the annual energy costA detailed analysis of the potential generation opportunity was completedInstallation and integration of the system was completed by a qualified engineering firmOperators were trained in the successful operation of the unit

Case Study Calgon CarbonThe Calgon Carbon Plant produces a wide variety of activated carbons, with more than 100 types of granular, powdered and pelletized product The system consisted of a single stage turbine coupled to a reduction gear and generatorA 22% increase in electricity rates prompted a look at ways to reduce energy costs The steam plant operates a waste heat boiler that produces ~ 50,000 lbs/hr of steam for ~ 8,400 hours per year.

Case Study Calgon Carbon Snap shot of savings Calculations

Calgon Carbon installed flow meters to measure hourly steam flow for an accurate generation modelTaking into account enthalpy lost through the turbine, calculations were made for make up steamAnnual generation at ~ 5,422 MWhs, saving more than $300,000

Case Study Calgon Carbon Environmental impact of onsite generation(Based on EPA eGRID 2007 Data)

By reducing their purchase of electricity by 5,422 MWh per year, this project reduces :NOx by 5 tons annuallySO2 by 8 tons annuallyCO2 by 3,014 tons annually This is environmentally equivalent to the annual CO2 absorption by approximately 362 acres of trees

Case Study Calgon Carbon Keys to their success

Electricity rates were increasing, and being proactive, they found a solution to offset their purchased energyInstallation of measurement equipment to accurately measure steam flow for 12 monthsThe staff was motivated to constantly seek out and identify cost saving opportunities, to protect sales margins against increasing competition from China and from cost of operation increases

QUESTIONS