approaches to residential energy storage · • tesla powerwall and other “in line” high...

Approaches to Residential

Energy Storage

Dane Muldoon

Quick Introduction

My Background

• Originally from the IT industry

• Have been in solar since 2007

• Previous experience in the solar retail sector

• [email protected]

Supply Partners

• Renewables & energy efficiency wholesaler

• Based in Brisbane servicing PV industry nationwide

• Full range of solar panels, inverters, batteries, etc.

mailto:[email protected]

mailto:[email protected]

The Revolution Will Be Televised

Public awareness

• Mainstream media is now regularly reporting on

energy storage

• Generous feed-in tariffs a thing of the past

• Increased cost of power

• Self consumption is now the GOAL for solar

Video – Media Coverage

Public awareness

• Supply Partners has over 500 customers that

regularly purchase

• Feedback is approximately 1 in 2 leads are

asking about energy storage

• Companies knowledgeable in energy storage

are reporting higher sale conversions

Why energy storage?

Energy Storage!

Why energy storage?

State of the Energy Storage market

Trends

• Consumer led – they’re asking for it before we’re even ready!

• A second boom?

• Everyone can see it coming but when will it get here?

• New technologies & business models

Technologies

• New battery technologies including:

– Lithium

– Ultra

– Flow

– Salt

• Hybrid inverters

• ESS units


Batteries – Lead Acid

• Obviously well known and well established technology

• Available in many, many different configurations and capacities

• Flooded, AGM and Gel cell options

• New variants coming to market including graphite (carbon) options

• Widest range of inverter / charge controller compatibility

• Very large installations are supported

• Best fit for off-grid and commercial UPS systems


Batteries – Absolyte


Batteries – Lithium

• The new “buzz word” battery technology

• Early customer concerns about safety largely overcome

• Everyone keeps one in their pocket!

• Inverter manufacturers have to confirm “compatibility”

• Quality / reliability / sophistication of BMS critical

• Higher power density (smaller size) and lighter weight than lead acid batteries

• Generally deeper depth of discharge and longer cyclic life than traditional options

• High voltage DC options coming


Batteries – LG Chem


Batteries – Flow

• Many people have heard of flow batteries but few examples in the field

• One example Redflow (ZBM) is a well known name in the industry

• Moving from R&D to commercialisation – units now built by Flextronics

• Cells can be serviced to extend life

• Energy can be stored almost indefinitely in liquid state

• More of an “energy” battery than a “power” battery technology

• Parasitic losses in having to run pumps need to be considered


Batteries – Redflow


Batteries – UltraBattery

• CSIRO technology now commercialised through manufacturer Ecoult

• Combines a lead acid battery with an ultra capacitor

• Reportedly highly efficient in a continuous partial state of charge operation

• “Ultraflex” residential product just released

• 40% depth of discharge puts their 48V unit at 11kWh useable (good size for residential)

• Very heavy (1190kg, lithium equivalent 120kg) so positioning needs to be considered


Batteries – UltraBattery


Batteries – Salt

• Aquion offer the Aqueous Hybrid Ion battery

• Residential product uses 2kWh stacks at 48V – larger stacks available as well

• Very high cyclic life and 100% depth of discharge using salt water

• Good temperature tolerance

• Not flammable, explosive, or corrosive and no dangerous or toxic components

• Large / heavy

• Have to see if manufacturing volume will allow for pricing to be reduced


Batteries – Aquion


Batteries In General

• Pretty big

• Pretty heavy

• Usually need to go inside

• Still too expensive to cover all energy requirements

• Pricing about right to target evening peak demand

• Peak demand tariffs will accelerate uptake


Battery Technologies

• Fantastic that there’s so many new products hitting the market

• …and new technologies being developed

• Way too soon to be picking winners and losers

• …but customers expect solar businesses to do just that!

What to do?

• What I like to do is follow the money…

• Who’s building new manufacturing capacity?

• Who are the largest companies (e.g. car makers) partnering with?

• What technology has the size to achieve economies of scale?

Three approaches to grid-connect

energy storage*

* These groups and the examples given are not exhaustive!


energy storage

Traditional Off-Grid

• Highly experienced manufacturers involved in off-grid for many years

• Lots of systems in the field

• Reliability of these products is critical for off-grid customers

• Flexible (single & three-phase) and highly configurable but complicated – training required


energy storage

Traditional Off-Grid Examples

• Schneider Electric SW & XW+ battery inverters and MPPT charge controllers (AC & DC coupled)

• SMA Sunny Island M & H battery inverters (AC coupled)

• Selectronic SP Pro battery inverters (AC & DC coupled)


energy storage

Hybrid Inverters / Batteries

• This is a new product category that’s emerged in the last two years

• Combines solar inverter and battery inverter/charger in one enclosure

• Entry point into energy storage by solar inverter manufacturer

• Hybrid Batteries combine energy storage and inverter/charger into one enclosure


energy storage

Hybrid Inverters - Examples

• Sungrow SH5K Hybrid (single phase 5kW)

• SolaX Hybrid (single phase 3kW, 3.7kW, 5kW)

• Solarwatt MyReserve – sits between solar panels and existing solar inverter

• Tesla PowerWall and other “in line” high voltage DC battery products

Sungrow SH5K Hybrid inverter 5kW solar / 65A battery

Our Sungrow + LG Chem System

LG Chem RESU 6.4EX lithium battery 5.8kWh useable

LG Chem RESU 6.4EX lithium battery 5.8kWh useable

SolaX SK-SU5000E Hybrid inverter 5kW solar / 50A battery / EPS

Our SolaX + LG Chem System


energy storage

Energy Storage Systems

• The “appliance” approach to energy storage where the manufacturer tries to keep things simple for the customer

• Single badge on the box means one company to turn to for warranty and service support

• Limits with flexibility and configurability


energy storage

ESS - Examples

• Samsung All-In-One 3.6kWh single phase

• Bosch BPT-S 5 Hybrid 4.4kWh – 13.2kWh single phase

Energy Storage – reality check

Strengths

• Consumer demand

• New solutions

• Falling costs

• Strong & agile industry

Weaknesses

• ROI relative to solar

• Customer price expectations

• Standards / best practice

Opportunities

• Partner with networks this time around

• New finance models

• Community ready this time

Threats

• Safety concerns and recalls

• Poor / non-compliant installations

• Customers invest in manufacturers that go bust

SWOT

A note on battery safety

CSIRO Report recommendations - 24th Nov 2015

1. Improve awareness of and access to information on the variety of battery energy storage technologies and their appropriate operation and care among consumers (general public), designers (engineers and electrical tradespeople) and installers (electrical tradespeople).

2. Research and identify the best methods for lithium-ion battery storage system recycling, and establish a lithium-ion battery recycling initiative.

3. Research and identify the best methods to safely (passively) extinguish domestic and small commercial scale lithium-ion battery storage fires.

A note on battery safety

CSIRO Report recommendations continued

4. Align Australian and international standards, and improve local regulatory and building codes relevant to energy storage systems.

5. Establish a set of best practices specific to the battery storage industry, including development and upkeep of an installation, maintenance and incident reporting database for energy storage systems in Australia.

6. Develop training and nationally recognised accreditation pathways for designers and installers specific to energy storage in domestic and small commercial scales.

Energy Storage – Financial Viability

• Return on Investment (ROI) with energy storage is

currently lower than the sale of a solar PV system by

itself

• PV systems commonly 4-6 years payback

– 16-25% Return on Investment (ROI)

• Energy Storage being sold today more driven by emotion

• Also increasing demand in weak grid areas

5kW PV with 5kW inverter Solar Only Solar + Batteries

Solar Production per day (kWh) 20 20

% used during the day 40% 40%

Used during the day (kWh) 8 8

Consumption (save $0.25/kWh) per day 2.00$ 2.00$

Annual benefit of PV Consumption 730.00$ 730.00$

% in excess of consumption during the day 60% 60%

Excess during the day (kWh) 12 12

Sold to grid (earn $0.06/kWh) per day 0.72$

Annual benefit of PV Feed-in-Tariff (FiT) 262.80$

Used at night (save $0.25/kWh) per day 3.00$

Annual benefit of Energy Storage 1,095.00$

992.80$ 1,825.00$

Daily extra benefit of Energy Storage per day 2.28$

Let’s talk about “Battery Ready”

Different Definitions…

• “It’s a solar inverter, just install any battery inverter later & your golden”

• “This manufacturer also makes a compatible battery inverter that you can install later”

• “It’s a hybrid inverter but you will need to invest in a battery management module”

• “It’s a hybrid inverter and there’s a battery inverter / charger built in”

Retrofitting batteries

What if someone already has solar?

• Lots of existing solar customers have now paid off their systems

• Lower / reducing feed-in tariffs encourage energy storage

• Is it best to add to an existing system or replace?

• Watch out for old systems needing to be brought up to current standards (earthing panels, etc)

Retrofitting batteries

Different Approaches

1. Add a battery inverter (eg. Schneider, SMA, Selectronic)

– Double check compatibility for best result

2. Replace existing solar inverter with a hybrid or add in a hybrid battery

3. Replace existing solar inverter with an ESS

4. Other solutions that aren’t even out yet!

Retrofitting batteries – battery inverter

Retrofitting batteries – hybrid inverter

Retrofitting batteries – hybrid battery

Retrofitting batteries – ESS

Off Grid Systems

What do we lose?

• Grid provides ∞ kWh

• Grid provides massive kVA

• No grid doesn’t just mean we need to provide kWh

Off Grid Systems Vs Grid Connect

Grid Connect

• 5kW Inverter (AC)

• 6kW Solar (DC)

• Surge – supported by grid

• Overnight power from grid

• Backup – none (typically)

• Solar cost: ~$7000

Off Grid

• 8.5kW Inverter (AC)

• 12kW Solar (DC)

• Surge – Inverter (12kW)

• Batteries (20kWh+)

• Backup – generator

• System cost: ~$50k - $80k

Thank You

[email protected]

approaches to residential energy storage · • tesla powerwall and other “in line” high...

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