Sign up to receive email updates, action alerts, health tips, promotions to support our work and more from EWG. You can opt-out at any time. [Privacy]

 

Methodology

Power Drain: Methodology

May 30, 2007

EWG requested documents from the Bureau of Reclamation under the Freedom of Information Act (FOIA) that would allow us to calculate the power rate charged to CVP farmers for the transportation and storage of irrigation water. We received a set of documents for fiscal years 2002 and 2003 titled "True Up of Estimated Costs Posted to Actual Costs." These documents contained the "Actual Total Energy" (in kilowatt-hours) and the "Actual Power O&M Expense" (in dollars) for each of the CVP's electricity loads. We derived the CVP power rate by dividing the power expense figure by the total energy figure for each load. We found that the power rate was the same for each load within a given fiscal year, and therefore used this figure as the CVP annual power rate.

Derivation of PG&E power rates

EWG relied on the historical tariff schedules posted on PG&E's website (available at http://www.pge.com/tariffs/electric.shtml#RESELEC) to derive average annual residential, industrial and agricultural power rates for the utility in 2002 and 2003. Specifically, we used the "Residential schedules E-1, EM, ES, ET," "Industrial / General Service (E20)," and "Small Agricultural" and "Large Agricultural" categories. When there were several different power rates charged to various subclasses of customers within a particular category, we used weighted averages based on how much electricity the company expected to sell to the various subclasses in 2006. These latter forecast figures were obtained directly from PG&E.

Derivation of power subsidy figures

For overall annual CVP power subsidy figures, EWG took the total actual Project Use Energy (PUE) costs for fiscal years 2002 and 2003 from Bureau of Reclamation irrigation Schedule B7 (available at http://www.usbr.gov/mp/cvpwaterrates/ratebooks). We then calculated the total number of kilowatt-hours (kWh) of electricity used by the CVP in a given year by dividing the total PUE cost by the CVP power rate for that year. To calculate the overall value of power subsidies in the CVP, we multiplied the total kWh figure by the difference between the PG&E agricultural power rate and the CVP power rate for that year.

For water district-level CVP power subsidy figures, EWG looked separately at water storage, direct pumping, and conveyance PUE costs. Reclamation reports the actual PUE costs for each district for water storage and direct pumping in Schedule B7, so we calculated the subsidy for these components in the same manner described above. For conveyance, however, Reclamation does not report the actual PUE costs in any of their publicly available documents so we had to rely on documents obtained via a California Public Records Act request from the Tehama-Colusa Canal Authority and the San Luis-Delta Mendota Water Authority. From these documents we were able to calculate the total amount of conveyance-related power costs charged to each water district, and subsequently calculate their power subsidy in the same manner described above.