Save50%ofthecostofasolarenergysystembyinstallingExSolar’s

Smart Energy Controller (Grid Tie Limiter)

• ForSolarTieGridconnectedsystems-eliminatingtheneedforbatteries.

• Forsystemswithpre-paidelectricitymeters.

• EuropeanInvertersofthehighestquality

• Fullmonitoringofthesolarsystem:

ü ACsinglephaseorthreephasecapability.ü DCMonitoringofVoltageandCurrent.

ü Detailedon-boardGraphicalReporting.ü PersecondMemoryCardLogging.

ü Dataexportforreal-timeDatabaseIntegration.

ü GSM,Wi-FiorEthernetmodulesavailable.

ü Networkaccesstodatainrealtime.

ü DynamiccontrolofFroniusGridTieInverters.

Thecomponentsthatmakeuparesidentialsolarsystemaretypicallydeterminedbythetypeof

electricitymeteratthepremises.Consequentlythetypeofmeterhasasignificantinfluenceon

theoverallsystemcostaswellasthetypeofinstallationperformed.Themainissueisthatpre-

paidelectricitymetersdonot“see”thedirectionofthecurrent.Henceinasolarsystemthathas

excessenergythatisunusedbytheclient,itispushbacktothegrid–thepre-paidmeter“sees”

thisenergyasastandardelectricityusageandthereforebillstheclientfortheenergythePV

systemsproduces(veryundesirable)!

Therearetwomaintypesofthegridtiesolarsystems;thosewith

batteries and those without. To date clients with a digital or

prepaidmeterrequiredasystemthatincludedbatteriesinorder

tostoreexcessenergyproduced–thispreventedtheenergyfrom

beingfedbacktoEskom.Unfortunatelyanysystemthatincludes

batteriesistypicallytwiceasexpensive.

Above:AsamplegridtiesolarsystemwhereStage1of the installation includesthesolarpanelsandaGridTieInverter(anoldelectricitymeterwouldthenturnbackwards).Stage2thenshowsthebatteryback-upsituation-inthecasewhenaPrepaidMeterispresent,bothStage1andStage2wouldhavetobeinstalledtopreventfeedingpowerbacktoEskom.

Sothechallengepresentedtoourengineerswastodesign

asystemthatwouldbeabletoworkwithaprepaidmeter

andpreventthisexcessenergyfrombeingfedbacktothe

grid.Aftertwoyearsofdevelopment,andincollaboration

withtheengineersatFronius,wehavedevelopedaSmartEnergy Controller (Grid Tie Limiter) that performs the

desiredresult!

ExSolar connects the Fronius solar grid inverter to the

Smart Energy Controller (Grid Tie Limiter), and it then has the ability to either re-direct the

overproducedenergytospecificappliance(likeageyserorapoolpump)orlimittheproductionof

the PVpanels tomeet the energy consumption needs of the client. This system is a very cost

effective solution for customers who are looking for a solar system that would lower their

electricity consumption but without the expensive batteries and a back-up system for power

blackouts.

Asyoumaybeaware,solarproductioninEuropehaspeakedinrecentyearsandasaresult,there

aremanyhighqualityGridTie Inverters (GTI)availableonthemarketatveryreasonableprices.

(GridTieInvertersallowtheindependentPVsolarsystemstobeconnectedtothegrid).

TheFroniusbrandfromAustriaisonesuchinverterthat,

combinedwiththestandard5yearwarranty(extendable

to 20 years), offers a great investment opportunity in

terms of a self-production solar powered system. The problem however is

that the South African government has not come to the party in terms of

allowingthefeed-inofunusedsolarenergybackintotheEskomgrid.Eskom

has however announced a feed-in tariff structure that is actually quite

laughable – not forgetting the fact that you have to purchase a new 4-

quaddrant meter AND pay a premium rate to have this facility available at

yourhouse.Theseadditionalcostsmakeittotallyunfeasibletoinstallasolar

systemandrelyonEskomrebatestofinancetheproject.

In light of the above problem, in conjunctionwith our existing Smart EnergyMonitor,wehave

developedanadditionalmodule thatdirectlycommunicateswith theFroniusGrid invertersand

backsdown(orlimits)thepowerproductiontomatchyourload.Thatis,astheloadinyourhouse

varies, theEnergyMonitorwill communicatewith theFroniusGTI andprevent feedbackof any

excessenergyviayourpre-paidmeter.

A screen-shot of one

systemwithoutthegridtie limiting function.Notice that the excess

energy is pushed back

to Eskom (negative

values).

The Yellow line is thesolarproduction,andtheRedlineistheEskomusage

In comparison, a system

withthegridtielimitingfunction.Noticetheredlinenever

goes below zero,

indicatingthatnoenergy

ispushedbacktoEskom.