IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Overview 1.Introduction / Summary 2.PV-diesel hybrid systems 3.Measurement equipment – chapter for electricians 4.Measurements 5.Short term evaluation 6.Long term evaluation 7.Incase of a blackout 8.Afterword 9.Templates

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Applicability of the guideline any type of PV system one or several liquid-fuelled and manually (or automatically) operated generators lead acid batteries of 12 V, 24 V or 48 V charge controller of series type DC or AC or mixed type of distribution network and system location in a tropical or sub-tropical environment at low latitude

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME System Components

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Analogy power system – water storage system

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME General explanations on PV-diesel hybrid systems Explanations on system components: PV panels, generator, battery, load, PV charge controller, inverter, AC charger, fuses Energy system balance System operation (when to charge batteries, when to start generator etc.) Maintenance (general explanations on various indications)

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME What measurements are required? Battery voltage measurement. Measured using a voltmeter or a multi meter. If charge controller or inverter displays the battery voltage or the battery state of charge, this value can possibly be used. Energy from PV. Measured using an accumulative DC energy meter. If the charge controller displays incoming energy from PV, this value can possibly be used. Energy from generator. Measured using an accumulative AC energy meter. If the AC charger displays incoming energy from the generator, this value can possibly be used.

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Energy to AC load. Measured using an accumulative AC energy meter. If the inverter is displaying energy going to AC load, this value can possibly be used. Energy to DC load. Measured using an accumulative DC energy meter. If the charge controller displays energy going to DC load, this value can possibly be used. Optional: Fuel consumption. Measured using an automatic fuel log. (Manual logging of all fuel fills can also be used) What measurements are required?

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Measurement equipment (chapter for electricians) Where and how to install measurement equipment What to explain to the operator: mark reading spots, note down readings, add values, create graphs, time for measurements, scale of graphs, system voltage, installed PV capacity, design value for share of PV, logging fuel) How to identify suitable scale for the graphs

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Identify suitable scale for graphs

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Where measurements are taken

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME When and how to take measurements How to make calculations Measurements

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME How to plot the obtained values in a graph Measurements

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Example: filled table and battery voltage graph

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Short term evaluation Evaluation of battery voltage graph (short term, every day) Evaluation of load & generation curves (as soon as battery voltage gives indication, at least once in a week) Is the system operated well? Can generation meet the load Can more load be connected (without extending operation of generators) Indication of failures in the system

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Battery voltage Dots always high up in white area: very good! maybe possibility to use generator less or increase load (analyse generation and load curve) Dot sometimes in grey or black area: should not happen too often (critical if more than 2 days in grey or black)

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Battery voltage Dots in grey are for many days: not so good, batteries working hard! Analyse generation and load curves to find problem; probably batteries are damaged or old Voltage decreasing over time: not good! Analyse generation and load curve and find problem!

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Battery voltage Voltage increasing over time: good! Batteries operating in a healthier and healthier way Today’s voltage lower than scale of template: either high load connected or battery voltage dangerously low; find the reason! Today’s voltage higher than scale of template: either measurement taken after sunrise or when generator was on OR error in measurement

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Evaluation load (black) & generation (yellow) Not good! Battery voltage certainly decreasing Good! Battery voltage certainly increasing (generation following load curve) Generation constant and load decreasing; probably battery voltage decreasing

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Long term evaluation Understand any changes over time: increasing load, degrading PV panels etc. Should be done every month; comparison with earlier months and years (also comparing average monthly & yearly parameters) Evaluation of battery voltage, load and generation, but also share of PV, normalised PV yield (energy in kWh generated per installed kW p per day), system losses, fuel consumption

IEA INTERNATIONAL ENERGY AGENCY PHOTOVOLTAIC POWER SYSTEMS PROGRAMME Calculations (e.g. monthly evaluations)