Boston Sand and Gravel Green Plan

Linda Charpentier, Boston Sand and Gravel
Beginning of a continuing process.
100 year old family run business in construction environment; very challenging environment.
Produce ready mix concrete, sand, stone.
Lots of logistics, on-road fleet, own small line railroad.
Have helped with the metrowest tunnel project, pumping concrete for a mile. Deer Island facility (set up mini concrete plant and used barges). Hancock Tower, Genzyme headquarters and more.
Green plan is 1 year old.
Use over a million gallons of diesel per year for truck and plant energy.
Charlestown plant uses a million gallon of waters per month.
Very involved in environmental compliance and being lean and green.
Staff of two in environmental compliance, OSHA, MEMSA, DOT, etc.
Charlestown Plant – I93 plant by Zakim bridge. Greening. Can get dollars on energy spent from accounting. Now working with accounting to calculate the volume of energy used. Energy procurement and demand response. Went after low-hanging fruit: lighting, pumps, motors and compressors. Also have what may be the largest solar, thanks to Mass Solar.
Gas used to heat water for production and for space heat.
Opportunity 1: gas heating replaced by waste oil from fleet – big fleet. 12% of natural gas replaced.
Opportunity 2: hot water control. Tempering valves on water tower. Modification to water feed control loop on boiler – 33% improvement in natural gas efficiency.
Energy Supply – Source One – organized multiple accounts to see where they are using their energy.
Lessons Learned: deregulation did not help. Price of energy is not fixed. Capacity tag – large companies have worked around the clock to change operations to off-peak. They can’t do this. Seasonal operations. Can’t operate 24×7. Do just in time – concrete must be prepared and delivered in 3 hours. Capacity tag during peak times killed them. Took half a dozen plants off supply contracts with utilities to save money.
Worked with Enernoc on demand response and facility based energy curtailment program. Taught them a lot about what is mission critical and what they could do without. Give back 850 kWh and get $17,000 check per year.
Demand Reduction – lighting. Prism Consulting providing turnkey service. Turn key service, paperwork for rebates, manifest for recycling. Total project cost of $65,000, out of pocket $39,000; and payback in 1.5 years.
Demand Reduction Equipment – boiler room pumps running all the time – $60,000 per year in energy. $8,000 investment saved $45,000 per year. replaced 2 compressors, saving 12,000 kWh per year.
Floated RFP for solar. 109KW system, generating 120,000 KWH/yr. 75% of annual garage energy. 5.5 year payback, 11.4% after tax rate of return. 40% rebate from state for the system. Solectria Renewables – AInverter, Evergreen – Solar Panels, Panel claw – panel mounting system. All MA based companies. Could not have done without MA Solar.
Awards:
Association of Energy Engineers – best energy reduction project in NE (81% energy reduction – PV Solar and lighting).
NRMCA (National Readymix Concrete Association) – Green Star Certification – 2nd company in US.