1. Energy Research & Development
SMUD
Energy Research & Development
In conduit / In stream Technology Assessment in SMUD’s Service Territory
Prepared by Lorraine White
August 2016

2. Background
SMUD’s goals include: facilitate a sustainable and low carbon future, enhance customer choice and support distributed and large scale energy resources in a reliable, sustainable and affordable way.
California’s sustainability and low carbon future includes a 50% renewable portfolio standard by 2030.
SMUD regularly evaluates technology advancements that will facilitate the transition and make it more cost effective.

3. SMUD’s AB 32 Water Energy Assessment
Opportunities exist to reduce GHG’s in Sacramento’s water systems
Many local water utilities have pumps, reservoirs and other infrastructure that can be used to manage local electricity loads.
SMUD should increase support for renewable generation co-located with water infrastructure and pursue demonstration of low-impact or in-conduit/in-stream hydro generation.

4. Project Objectives
The objectives for the in-conduit technology assessment are:
Identify state of the art and emerging in-conduit /instream technologies.
Assess cost, performance and market characteristics of these hydro technologies.
Determine potential sites for demonstration and deployment.
Evaluate economic feasibility of promising technologies for each potential site within the SMUD service territory.

5. Scope of Work Literature and Technology Review
Technical and Engineering Assessment
Approach & Assumptions
Findings
Equipment Selection
Model Levelized Cost of Generation
Capital and O&M Costs
Evaluate Ownership Options
Determine Benefits
Greenhouse Gas Reductions
District Benefits
Customer Incentives & Benefits
Provide Conclusions & Recommendations

6. Approach & Methodology1
Internet Research to Determine Available Technologies & Applications
Review Existing Studies & Interview Vendors and Manufacturers to Determine Commercial Status & Costs
Define Site Selection Criteria & Parameters 2
Solicit Water Utility Participation focusing on those who participated in the AB 32 Study
Gather Potential Site Data from willing Water Utilities
Select Preferred Sites based on Vetted Site Criteria 3
Determine Potential Capacity and Energy Generation of Possible Sites
Obtained Site Specific Equipment Estimates from Vendors
Evaluate Best Technology Applications based on Site Conditions
Prepare Site Development Inputs for Modeling Revenue Requirements 4
Modeled Levelized Costs of Generation and Sensitivities
Assess Ownership Options with Water Utilities
Assess Options to Facilitate Development
Establish a baseline of currently available technologies and commercial status through a interviews with vendors, literature and technology review.
Solicited involvement of local water agencies willing to participate in a demonstration of an in-conduit or in-stream generation project depending on their system opportunities.
Used SMUD and water utility data to calculate optimum generation capacity and annual available energy.
Working with willing water utilities, identified generation potential opportunities and sites.
Evaluated best technology applications for available sites.
Modeled the levelized costs of energy for these sites and associated sensitivities.
Recommended actions to facilitate potential demonstrations.
REPORT

7. Lit and Tech Review
In-conduit / instream generation has been in use for decades.
Identified 30 companies offering products & development services.
Three categories of technologies exist and have been demonstrated for various applications – both size and site conditions – successfully.
Conventional Small Hydro
Pumps as Turbines (PATs)
Hydrokinetic Turbines and Emerging Technologies
“Off the Shelf” technologies exist, but most customized to application.
Most successful applications have focused on 1 MW or greater applications in conventional site conditions.
Greatest opportunity to future development is in the Micro and Mini applications.
Source: SOAR

8. Many Conventional Types
Reaction Turbines
Impulse Turbines
Reaction Turbines: Francis, Kaplan
Impulse Turbines: Pelton, Turgo, Cross Flow

9. PAT Schematic
Source: worldwater.com
The impeller is used as the turbine typically with an induction motor used as an alternating current (AC) generator.

10. Installed in Existing System

11. Hydrokinetic/Emerging
Archimedean Screw &
Darrieus Type Hydrokinetic Turbine

12. Hydropower Classifications
Table 1-1. Hydropower Classifications by Size
Hydro Classification
Generation Capacity Range
Typical Applications
Potential Application within Sacramento Region
Large
Greater than 100 MW
Can be baseload generation feeding into transmission grid.
Not Applicable
Medium
~20 MW to 100 MW
Small
~ 1 MW - 20 MW
Usually feeds into a grid.
Applications possible if ~ 1+ MW site identified
Mini
~ 100 kW – 1 MW
Can be either stand-alone, mini-grid or grid connected (can feed in at the distribution level).
Very Applicable
Micro
~ 5 kW – 100 kW
Stand-alone on-site use, or distributed generation in urbanized areas; also small community or rural applications
Pico
Less than ~ 5 kW
Tends to be used in remote areas away from the grid.
Applicable; likely not cost effective

13. Applications
Source -

14. Benefits
Output is relatively predictable and can be a reliable renewable resource for on-peak and super peak capacity.
In-conduit, instream generation can be installed in existing systems resulting in minimal, low-impact or no disturbance and less regulatory burdens.
Can offset current power demands of water utilities within SMUD’s service area for sites, doubling benefits of the project: 1) reducing energy demand associated with nearby or associated pump stations and groundwater wells, and 2) producing clean, renewable electricity with no associated emissions.
In-conduit, low impact hydro development can assist SMUD in meeting its aggressive Renewable Portfolio Standard and Greenhouse Gas Reduction Goals.

15. 4 initially voiced interest
Invited all Water Utilities to Participation Who had Participated in the AB 32 study
6 responded
4 initially voiced interest
2 provided data
Source: GEI

16. Site Selection Criteria
All sites should ideally have relatively constant and uniform flows
Closed Pipeline, In-conduit Pressure Reducing Valve (PRV) Sites
Minimum flow of 2 mgd or 3cfs
>= 20 psi pressure drop
Minimum pipe diameter of 18-inches
Closed Pipeline, In-conduit, Pressurized Pipe Sites
Minimum flow of 2 mgd or 3cfs; Ideal of 10 mgd or 15 cfs
> 20 psi pressure drop; 40 psi is Ideal
Minimum pipe diameter of 8-inches
Open Channels, Canal Drops, and Gravity Flow Pipeline Sites
Minimum flow of 20 mgd or 30 cfs, with minimum differential elevation drop of 12 feet; Ideal is minimum flow of 65 mgd or 100 cfs, with minimum differential elevation drop of 20 feet
If gravity flow pipeline - minimum diameter of 24-inches; Ideal is 48-inches
Minimal and preferred

17. Energy Potential Capacity Factor = Average Annual Electricity (kWh/yr)
Used standard approaches to determine nameplate capacity and annual electricity generation
Monthly site flow records coupled with the daily diurnal or variability of flows that occur during on-peak and off-peak water delivery periods
Determined net head pressure values and pressure drops at site
Determined site sensitivities to fluctuation in flow and pressure
Capacity Factor = Average Annual Electricity (kWh/yr)
Nameplate Capacity (kW) x 8760 (h/yr)

18. Sacramento Suburban Water District Citrus Heights Water District
Potential Sites
Site
Existing Function
Approx . Gross Head (ft.)
Approx. Inlet Pressure (psi)
Approx. Outlet Pressure (psi)
Approx. Net Pressure (psi)
Ave Flow
(cfs)
Min Flow
Max Flow
Total Capacity (kW)
Ave Total Energy (kWh/yr.)
Average Annual Capacity Factor
Sacramento Suburban Water District
Antelope PRS
(48 inches)
Pressure Reducing Station (4 PRVs)
100
105 60 45
14.7 6 20
135 kw
503,379*
42.6%
Werner PRS
(30-inches)
PRV 55
4.1 2
38 kw
141,979*
42.7%
Citrus Heights Water District
30-inch Pipe at C-Bar-C Park
Excessive Pressure 90 64 26
8.9 3 13
54 kw
296,892
62.8%
24-inch Pipe at C-Bar-C Park
5.6 8
34 kw
185,558
62.3%
12-inch Pipe at C-Bar- C Park
1.4
0.5
2.2
9 kw
47,715
60.5%
ABOVE THREE SITES CAN BE COMBINED INTO A SINGLE SITE AS SHOWN BELOW.
42-inch Pipe at C-Bar-C Park
( combined) 16 24
96 kw
530,160
63.0%
Note: Ave Total Energy reflects 60% availability.
total generating capacity of more than 266 kW and an annual electricity production up to 1,175,520 kWh/yr

19. Findings
Application of commercially available technology is feasible within SMUD’s service area.
Two water utilities are willing to conduct demonstrations at any of six possible sites.
Only in-conduit projects could be investigated due to lack of broader agency participation, a short project timeline, and limited available site specific information.
Generation capacities range from 9kW to 135kW.
If all possible sites developed, generation could reach 1,175,520 kWh/yr.
Using SMUD’s 2015 projected emission factor lbs/kWh, this is equivalent to 536,037 lbs or 243 metric tons CO2 reduced annually.
Levelized costs of generation range from $0.12 to $0.71, all above SMUD’s target of $0.08/kWh revenue requirement.
Power is produced when SMUD needs it the most during the summer peak and super peak periods.

21. Barriers to Development
High costs of the interconnection process
Can range from $100,000 to $150,000
Can represent more than 1/3 the cost to develop a project
Lack of incentives to buy down initial costs
Currently no tax or development incentives
Grant funds are needed to offset costs
Restrictions on net-meter programs that prohibit pooling of accounts for demand offset
Lack of the availability of feed-in tariff agreements

22. Recommendations
Future exploration of in-conduit generation focuses on the major barriers to these projects identified in this study:
Cost of the interconnection process
Lack of incentives to buy down initial costs
Restrictions on net meter programs that prohibit pooling of accounts for demand offset
Availability of feed-in tariff agreements
explore allowing ownerships of these facilities by third parties
If grant funds become available, pursue most promising sites for a demonstration

23. Questions? Lorraine White Water-Energy Program Manager
cell:
GEI Consultants, Inc.
2868 Prospect Park, Ste. 400
Rancho Cordova, CA 95670
fax: