Outline

1. Epuron & TKLN site background

2. How CloudCAM is working to take on the role of smooth solar integration

3. Tidy hardware and lots of smarts - the physics of clouds

4. Remote sensing is flexible, can be updated in firmware and hardware and sneaks in at a fraction of the cost

5. Results to date at two sites

Wind Power (NSW) Solar Power (NT)

Epuron Pty Ltd

A leading Australian renewable energy company

Cullerin Range Wind Farm

Gullen Range Wind Farm

Silverton Wind Farm

Rye Park Wind Farm

Liverpool Range Wind Farm

Yass Valley Wind Farm

TKLN Solar (1MW)

Uterne Solar (1 + 3.1MW)

Yulara Solar (1.8MW) Total ~7MW Solar PV

TKLN consists of three projects located in Ti Tree, Kalkarindji and Lake Nash, all within the Northern Territory.

Together they sum to approximately 1MW

High penetration PV into diesel mini-grids (80% approx. max instantaneous)

Designed together by Epuron, PWC, CAT Projects and included federal government funding

Each site has a Grid Stability System (GSS) designed by MPower for short term solar smoothing

Each site has a 20 year PPA with PWC which includes ramp rate control

TKLN Site Background

We have been operating for > 3 years

PWC & Epuron relationship remains engaged & collaborative

PV & control hardware in good condition

Upgraded inverter communications to a cluster controller

Lead Acid VRLA batteries performance has degraded

More difficult to meet the ramp rate required in the PPA

Affecting yield

Difficult to manage large battery banks in remote locations

Replacement of batteries is a (slow) process currently underway

Current Status

Ti Tree Solar Power Station & Grid Stability System (GSS)

Epuron sister company Fulcrum 3D Pty Ltd has developed CloudCAM

CloudCAM is an optical camera that tracks clouds in the sky

ARENA 50% funded R&D project as part of the Emerging Renewables Programme

Epuron Solar Pty Ltd is a project partner

Installed easily on to a vertical mounting pole on the side of existing structures

Includes CloudCAM optical fish eye camera, pyranometer, temperature and humidity, logger, remote comms

CloudCAM has now been installed at Ti Tree and Kalkarindji and integrated with the existing solar power station control system

What is CloudCAM

Installation at Ti Tree NT

How CloudCAM is working to take on the role of smooth integration

Historically we have used lead acid batteries to smooth the solar generation during cloud events:

Cloud detected; predictive

ramp-down commences; cloud

clears; ramp up and resume

normal operation

Note different ramp-

up and ramp-down

rates are allowed for

in this design.

Cloud detected; predictive

ramp-down occurs until solar

output reaches “safe” level

Cloud clears; ramp up and

resume normal operation

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How CloudCAM is working to take on the role of smooth integration

We are now using CloudCAM as an alternative method to deal with cloud events:

CloudCAM at Ti Tree and Kalkarindji are currently working in ‘NowCasting’ mode

CloudCAM takes an image every 6 seconds and runs an algorithm to determine if it is currently cloudy or clear

The CloudCAM hosts a Modbus TCP register which is queried by the TKLN control system

This ‘clearsky’ flag is used by the TKLN control system to ramp up or down solar output at controlled rates

Thumbnails of images are sent every 6 minutes to Fulcrum3D server

CloudCAM will soon be operating in ‘Prediction’ mode

Each cloud is individually identified and mapped

Movements of clouds is tracked between images and predicted

CloudCAM will give an output for the solar resource in 30 sec, 1 min, 5 min etc

Yield lost by reduction of solar output before a cloud is offset by not needing to inefficiently charge and discharge batteries

Using CloudCAM instead of batteries

Example of CloudCAM thumbnails

Clear

Cloudy

Tidy hardware & lots of smarts – the physics of clouds

Types of sky & clouds

Examples

Impact on solar output

Difficulty in detection

Speed of clouds as function of height

Height of clouds relating to shadow location

Types of sky & clouds

Clear

Can set solar to maximum power

Wispy clouds

Have minimal impact on solar output

Are difficult to detect

Sometimes purposely not detect due to minimal impact on solar output

Often looks like glare

High clouds

Has small - medium impact on solar

Increases brightness in area around sun

Types of sky & clouds

Partly Cloudy

Full, dark, lower clouds

Distinct cloud groups

Very high impact on solar output

Easier to detect but also can be fast moving

Very dark regions on bottoms of clouds can look similar to ‘clear sky’

Cloudy

Full cloud cover

Medium impact on solar output

Can be minimal unless break in clouds occur

Difficulty in detection

Clouds at different heights can move independently which can make cloud

detection and prediction more difficult.

See example below from 25th Feb 2016 at Ti Tree

Speed of clouds as a function of height

The speed of clouds changes as height increases

This means the expected time before cloud events changes upon cloud height

Geographical location and time of year changes cloud speed

For the NT in Australia, wind speed is faster in winter

This is good because this is the dry season

Data for graphs on the right from the International

Standard Atmosphere ISO 2533:1975

Speed of clouds as a function of height

Transit time of clouds can then be determined as a function of cloud height

The graphs on the right are the time taken for a cloud to travel across ¼ of the camera lens

This kind of information is important for transitioning from ‘NowCasting’ to ‘Prediction’

The vertical lines represent 5 minutes and 10 minutes

Data for graphs on the right from the International

Standard Atmosphere ISO 2533:1975

Tidy hardware & lots of smarts – the physics of clouds

Intelligent part of CloudCAM mostly on the software side

Future development of CloudCAM can be tested historically to previous images

This can be applied to existing installations remotely

Remote sensing is flexible, can be updated in firmware and hardware and sneaks in at a fraction of the cost

CloudCAM can be easily installed, attached to existing buildings, containers or met towers. All it requires a fairly unobstructed view of the sky

CloudCAM comes with the optical camera, the pyranometer and the temperature and humidity sensor which connect to a Fulcrum3D designed and built logger

F3D logger is then connected to the local network via LAN cable and to a 12V power supply

Local hardware is reliable and robust without moving parts

CloudCAM software operates independently & locally with the local PV control system

CloudCAM firmware can be updated remotely

Remote sensing is flexible, can be updated in firmware and hardware and sneaks in at a fraction of the cost

When TKLN was built, the GSS at all three sites cost a combined ~$1M

CloudCAM costs in the order of ~$30k-$40k

CloudCAM can drastically reduce the need for batteries, or remove them altogether depending on the type of project

Perhaps the best combination, depending on the project, is high penetration of PV into diesel mini-grid with much smaller (and affordable) battery support with a CloudCAM

Epuron Solar is currently trialling the CloudCAM with various levels of battery support to see what works best

Results to date at two sites

Yield was decreasing towards the end of 2015 due to battery degradation (more than usual for the wet season)

CloudCAM was first operational in December 2015 but not integrated with the solar control system until the start of January 2015 at both Ti Tree and Kalkarindji

For January 2016 in comparison to December 2015 at Ti Tree, CloudCAM has caused an 4% increase in yield, normalised for variance in monthly irradiation

For January 2016 in comparison to December 2015 at Kalkarindji, CloudCAM has caused an 5% increase in yield, normalised for variance in monthly irradiation

Both sites have had significant decrease in battery cycling which will help preserve battery lifetime

Results to date at two sites

CloudCAM detecting

clouds then clear sky.

Minor yield lost

Complete elimination of

battery use on this day

Results to date at two sites

Significant fluctuations

avoided; minor loss of

production

Dramatic reduction in

battery cycling; dramatic

reduction in battery

capacity required