UNM ME 217 Energy, Environment & Society

Renewable Energy and the Need for Energy gy gyStorage

November 8, 2011Steve Willard, P.E

Renewable Energy and the Need for Energy gy gyStorage

Wh t f t i t• Where we get our energy from, constraints and the mandates for the future

R l h t Utiliti h t d t k th• Rules – what Utilities have to do to keep the Energy Grid operating

• Impacts of Renewables• Impacts of Renewables

• Need for Storage

• Solutions - What’s available - Whats being done

The US Energy

s

gyGrid – Current

Snapshots

Transmission Network – very interconnected

Generation Assets-mostly relying on fossil based resources

What's Changing?– Drive to Renewables

Mandates for Renewable Energy - Changing the Mix of Resources

New Mexico’s Renewable Portfolio Standard

3,000

NM RPS•2011 – 10% of retail load

2,500

3,000

•2015 – 15%•2020 – 20%

NM RPS 1,500

2,000

GW

h

NM RPS Distributed GenerationBreakdown or “C t ”

1,000

G

“Carve outs”•2011 - 1.5% of total RPS •2015 - 3%% -

500

2008 2011 2014 2017 2020 2023 2026

Current Net Electricity Generation by Energy

Energy SourceNet Electricity

Generation (GWh)Percent of Total Net Generation

CCoal 2,000,000 48.5Petroleum liquidsa 31,200 0.8Petroleum coke 14,200 0.4N t l 877 000 21 3Natural gas 877,000 21.3Other gasesb 11,600 0.3Nuclear 806,000 19.6Hydroelectric 248 000 6 0Hydroelectric 248,000 6.0Other renewablesc 124,000 3.0

In a general sense this has to

Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use (2010), National Academies Press

sense this has to change to 20% by

2020

Rules of the Game – Accommodating Renewables is not easy

• Resources have to match load – alwaysT i i L l Hi h V lt F d l (NERC)• Transmission Level – High Voltage – Federal (NERC) Jurisdiction

• Mistakes can cascade and cause big problems – refer to th i t t d T i i N tthe interconnected Transmission Networ

• Straying from this invokes serious penalties ($M enforced by Federal Regulators)’

• Customer Loads are very sensitive (and growing more sensitive) and have to be served with quality powerwith quality power • Distribution Level – Lower Voltages

• NMPRC Jurisdiction• NMPRC Jurisdiction

Key Rule – Load must match output of generation resources 24/7/365/86400resources 24/7/365/86400

Wind Variability – Transmission Level Impacts

150

200

Wind Farm Output

50

100

-50

0

10/16/2003 9:41:18 AM 10/17/2003 9:41:18 AM24.00 Hour(s)

-100

-150 Area Control Error (ACE).

NERC CPS-2: The average ACE for at least 90% of a clock-ten-minute periods during a calendar month must beNERC CPS 2: The average ACE for at least 90% of a clock ten minute periods during a calendar month must be within a specific limit. PNM’s current limit is 38 MW.

ACE deviates by more than 40 MW as a result of rapid changes in wind power output, affecting CPS-2 for this sample month (average CPS-2 was still above 90%)

10

How the Match is Made – Resources Used to Match Load

Coal Resources have to be turned downbe turned down

Solar PV Variability - Distribution Level Impacts Prosperity Energy Storage 11/5-6/2011p y gy g

A i l 1MW PVA single 1MW PV resource (distributed generation) can

push a feeder into high penetration

Potential Solution to Renewable Intermittencyy

Match Load to Resource •Shape the Load to Resource

•Load Modification - Invoke Real Time Pricing (Smart Grid) •Load Reduction

•Shape the Resource to the Load •Curtail Renewables•Energy Storage

Storage TypesBatteries

Multiple types of chemistries - Lead Acid- Lithium Ion- Flow Batteries - Sodium Sulfur- Others

ThermalThermal Ice Chilled water/hot waterMolten Salt (CSP application)Molten Salt (CSP application)

FlywheelsSupercapacitors/UltracapacitorsCompressed Air Energy StorageCompressed Air Energy Storage

(CAES)Pumped Hydro

Storage Costsg

Battery Storage

•Numerous Chemistries Emerging – some being Substantiated

Lithi B d•Lithium Based

•ZN Air

•Liqud Metal•Liqud Metal

•Zn BR

•NaSNaS

•Va Redox

•Advancements from Traditional

•Advanced Lead Acid

Compressed Air Energy Storage

• Large Transmission scale storage

• Requires appropriate geology to tsupport

Wh t’ b i d ?What’s being done?PNM/UNM/EPRI Smart Grid Demo Feeder ModelingCommunication/control system architecture

PNM/UNM/DOE – Prosperity Energy StorageOne of 16 DOE Smart Grid Storage Demonstration Projects

PNM/DOE Smart Grid Demonstration Objectives

Create a dispatchable, renewables-based peaking resource

Combine PV and storage at a substation to achieve a minimum

j

Combine PV and storage at a substation to achieve a minimum of 15% peak-load reduction on an associated distribution feeder

Demonstrate that this combination can mitigate voltage-levelDemonstrate that this combination can mitigate voltage level fluctuations as well as enable load shifting

Quantify and refine the associated performance requirements, operating practices and cost:benefit particularly for regionsoperating practices, and cost:benefit, particularly for regions well-suited for distributed generation

Generate, collect, analyze and share resultant data

Enable distributed solutions that reduce GHG emissions through the expanded use of renewables

Modeling – Key to Field SuccessSuccess

UNM Base Effort

Utilizing Leading Edge Distribution System Models

Allows understanding of control methodologies

Allows quicker assessment of benefitsAllows quicker assessment of benefits

Allows results to be transferable to the Utility Industryy

Feeder to be ModeledNormally Open

switch to Sewer Plant 14

Normally closed switch

Normally closed

switch to

St di

Sewer Plant Substation Feeder 14

Switchgear

PNM

Sewer Plant 14 closed switchswitch to Studio 14 To Studio Substation-

Feeder 14

Studio Substation –Feeder 14

PNM installed

PV + Battery

Fraunhoffer Solar Test Facility

Phase 1 Residential

Battery Storage

Test Facility

Albuquerque

Site for MdS/NEDO commercial Energy Efficient building

Residential (Under Construction)

Albuquerque Studios

Town Center

Energy Efficient building Construction)

Load shifting algorithmsLoad shifting algorithmsSeveral strategies for load

shifting:• Set time charge/ set time

discharge• Estimation of peak load ½• Estimation of peak load ½

day ahead• Estimation of PV energy

production based on the weather report and other

information• Estimation based on

TOD/pricing info 1-1½ day aheadahead

Modeling: Shifting algorithmModeling: Shifting algorithm

241-4908

Prosperity Energy Storage Project FeaturesProject Features

Schematic of theSchematic of the Prosperity System

500kW Central Inverter

Fixed Voltage 800 VDC (+/‐400VDC)

835kVA, 750kWGrid‐Tied Inverter

BESS Master Controll

er

BES System supplied byEPM/Ecoult

(+/ 400VDC)

250kW DC Converter with Power Regulator

500kW DC Converter with Power Regulator

er

500kWp Solar PV Array

Peak Shifting – 990 kWhr Containerized Advanced Carbon VRLA 

Battery (6 x CABS)

Power Smoothing – 500kW Containerized  VRLA UltraBatteries 

(2 x CABS) 

Details – Data Acquisition System Specification/Engineering Archtecture Diagram

Applying Storage – Commissioning Data Shifting and Smoothing Batteries Commissioned andShifting and Smoothing Batteries Commissioned and

dispatching to grid - data from Saturday 10/15/11

Data set from 9/22-9/23

• Algorithm DevelopmentNext Steps - Implementing Test Plans

go t e e op e t• Shifting – coded V1 in place – will test various inputs and filters throughout

test period

• Smoothing – data structure assembled to align next day forecast with• Smoothing – data structure assembled to align next day forecast with historical load/price history

• extensive data correlation of historical price/load history completed

• Result forecasted to be multi variant /optimization based algorithm• Result forecasted to be multi-variant /optimization based algorithm –extensive effort – start simple and grow in complexity

• Test Plans Aligned to seasonal load and PV output

• First of five test plans being initiated• Smoothing – Oct through Dec 2013

• Peak Shaving – winter and summer peaking period 2012-2013Peak Shaving winter and summer peaking period 2012 2013

• Firming – summer 2012

• Arbitrage – Shoulder periods throughout test period

All of the above summer 2013• All of the above – summer 2013