DOI: 10.29302/Pangeea 19.08

INTEGRATION OF HYDROPOWER, WITH SOLAR AND WINDRENEWABLE SOURCES. INTELLIGENT ENERGY SYSTEM IN

VANATORI -NEAMŢ NATURAL PARK, ROMANIA

Assoc. prof. COSTEL BOARIU, Technical University Gh. Asachi of Iasi, Romania

Stefan cel Mare University of Suceav, Romania

ABSTRACT: In Romania there are hundreds of isolated areas with limited access toutilities, most of them being protected natural areas: national and natural parks, Nature 2000Ecological Network areas for which the biodiversity conservation is a high priority.

This article aims to present an environmentally friendly solution for providing energy inprotected natural and mountain areas. The developed model is a smart energy system basedon increasing the use of energy potential from renewable sources: hydropower, solar energy,wind energy, in an isolated area of Vanatori Neamt Natural Park, Romania, by using lowenergy power sources to potentiate a higher energy power source.

The model allows energy conservation and includes a distribution network. Thechallenges were to find an optimal solution for energy storage and to minimize environmentalimpact. The purpose of developing this model was to capitalize renewable energy sourceswithin protected areas in order to secure the electricity needed for those consumers whoeither cannot be connected to the national energy system or their connection is veryexpensive or the quality of the provided energy would be very low. Both in the constructionphase and in the operational phase, it will not cause any environmental impact, asdemonstrated in the Environmental Impact Assessment Study

Keywords: hydropower; pumped-storage; renewable electricity; energy managementsystem;

1. Introduction

The background of this research is theworldwide increase in the use of renewablesources inside of hybrid power generationsystems. As mentioned in the EnergyStrategy of Romania 2016-2030, "theenvironmental impact of the energy sector isa basic concern of the Strategy, reflected inthe strategic objective of sustainabledevelopment through the protection of theenvironment and the limitation of globalwarming"[1]

Within the context of the strategicobjective of sustainable development and inorder to respond to the need for energysupply in isolated areas, we are seeking amodel of a renewable energy system based

on the potential of the area - hydropower,wind energy and solar energy.

SEI - Intelligent Energy System inProtected Areas was a Romanian-Norwegianresearch project in the field of renewableenergy, funded by the European EconomicArea Financial Mechanism 2009 - 2014. Thepromoter of this project was "GheorgheAsachi" Technical University of Iasi, alongwith partners from Norway: SINTEF EnergyResearch (Trondheim), NorwegianUniversity of Science and Technology andpartners from Romania: PolytechnicUniversity of Timisoara, PolytechnicUniversity of Bucharest, Administration ofSiret Water Basin, Bacau, ROMSILVA -V a n a t o r i Nea mt Na t u r a l Pa r kAdministration[2].

Integration of hydropower, with solar and wind renewable sources 55

In Romania there are hundreds ofisolated areas with limited access to utilities,most of them being protected natural areas:national parks, natural sites, Nature 2000Ecological Networks, areas for which thebiodiversity conservation is a high priorityand where there are restrictions oninfrastructure development regardless on itspurpose.

According to the National Strategy andAction Plan for Biodiversity Conservation2014-2020, one of the threats to biodiversityin Romania is the execution of extensivehydro-technical works for the building wateraccumulations and protection against floods.

The surface of the national protectedareas reported to the surface of Romania is7% (1,663,360 ha) and the total surface ofNature 2000 sites, compared to the surface ofthe country, is 22.68% (5.406.000 ha) [3].

The measures stipulated in themanagement plans of the protected naturalareas are designed to take into account theeconomic, social and cultural requirements,as well as the regional and localparticularities of the area, priority beinggiven to the objectives that led to theestablishment of the protected natural area –biodiversity conservation.

The aim of the research was to identifyan intelligent energy system model, that: a)allows the use of small, renewable energysources to potentiate a higher power energysource, b) allows the energy conservation,including a distribution network. The role ofthis model is to provide the necessaryelectricity for consumers, who either cannotbe connected to the national energy system,or their connection would be very costly orthe quality of the delivered energy would bevery low.

The intelligent energy system forVanatori Neamt Natural Park in Romaniaincludes hydropower, solar energy and windenergy, as renewable energy sources,defining both the infrastructure and theequipment needed to produce green energy.

If the main objective of the research was

to identify a system model that would allowto increase the use of energy potential fromrenewable sources in isolated areas locatedespecially in protected areas by using lowpower energy sources to potentiate a moreenergy, the specific objectives are: (i) todevelop a smart environmental friendlyenergy management system model that canbe applied in the protected area; (ii) carryingout a study of the hydropower potential of thepermanent natural water course in thecontext of climate change; (iii) developmentof alternative energy storage methods; (iv)the development of a smart dispatcher energysystem and of a distribution micro-network;(v) developing a management strategy for theintelligent energy system; (vi) developmentof systems that integrate several types ofelectricity generators - micro-hydropowerplants, wind turbines, solar panels, dieselgenerators; (vii) the development of ahigh-power electricity generation system forshort periods of time using low-capacity, butlong-term power sources.

This is a complex approach to respond tothe needs for sustainable development in aprotected natural area through a solutionwithout significant environmental impactand which does not affect the conservationstatus of protected species and exploits theexisting energy potential in the area, in thepursuit of economic efficiency.

The hydropower component is essentialin the developed model, being necessary thestorage of the produced electricity as waterpotential energy. According to the model, thewater is captured from the river during thehigh flow and stored in ponds. Later insunless and / or windless periods thepotential energy of the water is transformedinto electricity, passing water from the upperbasin into the lower basin by means of areversible turbine or an SHP (figure 2).

Hydro-energy is a renewable energysource based on water drops, with specialfeatures, not only providing clean energy butalso providing indispensable services to theenergy system.

Costel Boariu56

Advantages of using hydropower:economic advantage, high yield, low cost,long life; ecological advantage, does notpollute the environment.

Disadvantages of using hydropower:sometimes hydro facilities can generateconflicts when placed in national / naturalparks or when the water level of the damcovers localities; the modification of thesurrounding biotope, the necessity ofbuilding areas land expropriations, droughtsthat may dramatically decrease the lake level[4].

Hydropower production is based onefficient and reliable energy productiontechnology in terms of clean energy. Inparticular, the essential benefits ofmicro-hydro potential compared to wind,wave and solar energy are [5]: • high yield (80-90%); • high transformation factor (generally>

70%), compared to 18-22% for solarenergy and 30% for wind power;

• high predictability, varying annually withthe amount of rainfall;

• energy produced varies only daily (notfrom minute to minute);

• good correlation of demand and supply; • long-life, robust lifecycle technology that

can be up to 50 years old or even longer.Actually, the general perception in

Romania is that micro-hydropower plantssituated on mountain rivers destroysbiodiversity in protected areas; habitats, fish,otters and wildlife are generally threatened.

The energy system model obtained is acompromise between: 1. the benefits of thehydroelectric infrastructure in terms ofelectricity generation, 2. the combination ofseveral types of renewable energies, allowingthem to be stored, 3. the development needsof the communities in protected areas and 4.the impact in terms of territory, ecology andhuman values.

Globally, there are multiple energystorage solutions. The most common form ofstorage involves pumping water to areservoir located at a height when demand

for electricity is low and its release intohydro generators when electricityconsumption increases.

In Ireland, a think tank called Spirit ofIreland is working on such a project, a 3.6billion-dollar business that will use thepumping storage method to make the most ofthe country's intermittent winds."Inappropriate" energy from large windfarms will be used to transport sea water to ahigh-pitched tank [6].

At the Dinorwig power plant in the UK,for example, water is pumped into areservoir on top of Mount Elidir Fawr duringperiods of low consumption. When energyconsumption reaches high levels, water isreleased from the mountain to start theturbines that supply the power grid. But notevery country can rely on pumping storage,which is overwhelmingly dependent onexisting geographic features [6].

The Canadian company Hydrostorinvented a system of underwater balloonsunder pressure that could store renewableenergy until needed, which could reduce theneed for gasoline or gas as an alternativecalorific source. This solution could conserveenergy for a time twice as long as the mostpowerful battery we have today and at amuch lower cost. The first experiment wasalready set up in Lake Ontario near Torontoin Canada with a series of balloons set at 55meters deep and connected to the gridthrough a duct [7].

Battery storage is a widely-used methodbased on ever-developing and evolvingtechnologies. Batteries and accumulatorshave a limited life span and at the end oftheir operating cycle they become hazardouswaste.

In Romania there are hundreds ofisolated areas where access to utilities islimited. Energy storage technologies andtechnologies for integrating renewableenergy sources at a global level make itpossible to develop autonomous systemsbased on renewable sources for ruralcommunities or small residential complexes.

Integration of hydropower, with solar and wind renewable sources 57

2. Materials and methods

The Intelligent Energy System modeldeveloped for Vanatori Neamt Natural Parkin Romania, puts together: • exploitation of the renewable energies

potential - hydropower, wind energy,conventional energy (conventionaldiesel), integrating several types ofelectricity generators;

• alternative energy storage - storage bypumping and storage in batteries;

• intelligent energy dispatcher type system; • micro-distribution network; • producing high power energy for short

periods of time using low-capacity, butlong-term power sources.

The model is adapted to regulations onprotected natural areas and topology specificto isolated, mountainous areas with limitedaccess to resources and infrastructure.

The key elements that define the areas ofinterest for the implementation of intelligentenergy management systems are: (i)geographical isolation; (ii) lack of telephonenetworks; (iii) the location in protected areasof human settlements in need of electricityand access to information; (iv) the lack of thepossibility of linking to the national energysystem or the very high cost of theconnection; (v) topography favorable to theinstallation of the system in the protectedarea.

Following the application of the abovecriteria, it was identified as a location for themodel development the Vanatori NeamtNatural Park, the area taken into account inthe research, belonging, from aterritorial-administrative point of view, tothe Crăcaoani commune, the Neamt County,the North-East Region.

Coordinates of the site are: Lat.47º.04'.38,00 "N, Long. 26º.08'.59,00 "E.

Beyond technical details, which arelinked to dozens of concrete items (capturethreshold, top basin, bottom basin,micro-hydropower, emergency diesel

generator, solar panels, wind turbines,energy storage elements, networkdistribution system, radio system, researchlaboratory building, pipelines, consumers,accessories and control and actuationelements), we underline that the aim is tofully ensure the role of the intelligent energymanagement system, namely the monitoringand control of the flow required for the microhydro power plant in relation to the demandfor energy, but also the flow compensationbetween pools in relation to the volumerequirement of the upper basin. At the sametime, monitoring covers the energy stocks inthe batteries and the distribution andcompensation of energy production amongt h e s ys t e m ' s e n e r g y s o u r c e s(micro-hydropower, solar panels, windturbine etc.).

The role of the system in question cannotexceed the consumer interrogation withregard to the required energy demand andproviding safe operation conditions in theabsence of the required amount of energy.

From the practical point of view, it canalso produce electricity by using the waterdrop from the upper basin in the lower basin.The fall is generated by the opening of acontrollable solenoid valve that allows avariable flow rate. The amount of energyproduced and, incidentally, the volume ofwater used will vary with the consumerdemand dictated by a final consumer (groupof consumers). If the upper basin flow fallsbelow a minimum allowable level, it will bepumped (using renewable energy - solar,wind) from the lower basin.

As far as the distribution management isconcerned, it will be achieved by using allt h e s y s t e m e n e r g y s o u r c e s(micro-hydropower plants, solar panels andwind turbines), including storage batteries.In the event of an emergency, a dieselgenerator will operate; the control of thewater flow in the system is based on theaction of electric valves, fully automatic, inrelation to the energy requirement at a givenmoment.

Costel Boariu58

Fig. 1. Building solution - Situation plan

The constructive solution of the modelincludes 3 infrastructure objectives (Fig.1):

1. Intake and supply with the followingobjects:

Object no. 1.1. Water intake in the riverbed Bouletul Mic at elevation 770.25;

Object no. 1.2. Adduction with PEHDpipe, underground

2. Storage tanks and energy laboratorywith the following objects:

Object no. 2.1. Supply water basin: upperbasin, drainage system 1, drainage system 2;

Object no. 2.2. Lower storage basin(water elevation at level 767.00);

Object no. 2.3. Penstock PEHD pipeline,underground;

Integration of hydropower, with solar and wind renewable sources 59

Object no. 2.4. Energy laboratory locatednear the lower basin: Infrastructure,superstructure, sanitary and electricalinstallations, equipment (including turbinemicro-hydropower / reversible pump, storagebatteries, monitoring equipment, command/ control equipment and power distributionpanel);

Object no. 2.5. Protection of the left bankof the river Boulevul Mic with bio structures(live cribwall):

Object no. 2.6. Technological road3. Energy system based on renewable

energy sources with the following objects:Object no. 3.1. Solar panel batteries and

interconnection equipment;Object no. 3.2. Wind turbine and

interconnection equipment.Intake: the water captured at elevation

770.25 in the Bouletul Mic river bed will beled through the underground pipe to thelower storage basin. The length of the feedwill be 78 m. The pipe path will be straightfrom the exit of the loading chamber to thelower basin near the laboratory. Theadduction leaves the loading chamber atelevation 769 and flows into the laboratorydorm, then into the lower basin at the level767.00.

The lower basin (level 767.00) shaped asa cone trunk - in the basin axis will be fittedwith a PEHD D315 pipe for emptying /washing the basin. The water inlet into theduct will be through a drainage holeprovided with a plug and chain anchored bya float. The volume of water that can bestored in the lower basin is about 1500 m3.

The laboratory, located near the lowerbasin, is a construction with metallicstructure. Inside the laboratory will beinstalled the functional equipment: • reversible turbine / pump, SHP2, which

will also be able to measure the amountof water that will circulate in the PEHDD355mm pipe, by falling / pumping - wewill use a reversible pump with lowoutput as turbine, approx. 80% of pumppower;

• LPG-based heat generator group; • batteries for electricity storage; • SHP1 power micro-power plant; • an array of monitoring, control and

command equipment; • dispatcher - hard - data processing

equipment, with data transmission /acquisition boards;

• distribution panel; • appropriate furniture.

The upper water storage basin will havethe shape of a rectangular pyramid trunk. Thelong side of the basin will be parallel to thelevel curves. The water level at NNR will be796.70. The volume of water stored in thepool will be about 800 m3. The height ofsafety between the NNR and the upper edgeof the basin will be 30 cm.

The penstock, 198m long undergroundPEHD pipe, will lead from the upper basin tothe energy lab.

The parameters of the model project are:the installed flow rate, Qci = 150 l / s, theupper basin will have a capacity of about 800m3 - the equivalent of 70 KWh, the turbine /reversible pump will have the installed powerPi = 2,5kW / 3,0 Kw , the lower basin willhave the capacity of 1600 m3, the installedflow rate of the reversible pump will be Qi =45 l / s, the wind turbine will have the powerPe = 400 W, the solar panels will have thepower Ps = 15 kW.

It will produce energy through the fall ofthe water stored in the upper basin (volume800 m3), using the wind turbine to producewind energy and using the solar panels. Partof wind and solar energy is consumed forrising water by pumping it from the lowerbasin into the upper basin

In the area of the project site dominatesthe natural environment, and on a limitedarea, there are the buildings of the monasticsettlement Bouleţ hermitage. The site islocated on the surface of the Vânători NeamţNatural Park, which has an internal zoningaccording to the Government EmergencyOrdinance no. 57/2007 approved withamendments and completions by Law no.

Costel Boariu60

Fig. 2. Habitat 6520 Mountain meadows in Vanatori NeamtNatural Park in Romania

49/2011, as amended and supplemented.Thus, the surface of the Vânători Neamţ

Natural Park is divided into three areas: • full protection area - 615.5 hectares; • buffer area - sustainable management

area - 27,785.3 hectares; • sustainable development area - 2,230.2

hectares.According to zoning, the research site is

largely in the area of sustainabledevelopment - the Bouletul Mic Hermitagewhich includes part of the meadow ofCrăcăoani commune and has an area of 1.3hectares. The projected objectives occupy anarea of approx. 3509 m² in habitat 6520Mountain meadows (Figure 2)

3. Results

The proposed smart energy system includes: • The equipment solution - transposed into

the block diagram of the system; • Energy system management – dispatcher

and software solution

The equipment solution for the model isshown in Fig. 3.

The consumer community that addressesthe developed model will have a relativelyatypical consumption profile due to the factthat the necessary energy will also be used forenergy-producing but not continuousactivities. Due to the fact that the system isproposed to be a 100% autarkic, 100%reliable and at the same time one that bymeans of monitoring, remote control andcreation of the possibility to simulatedifferent situations from the computerterminal, is at the same time a subject ofstudy accessible to groups of students in thefield laboratories.

In line with the current requirementsaiming to reduce pollutant emissions and

integrate this symbiotic system into a naturalsetting, the following concepts were the basisfor the concept: • Electricity to be generated by 3

independent energy sources (hydro / wind/ solar);

• In case of exceeding the estimatedconsumption during the study period andin the idea of not leaving the communitywithout energy, a diesel-electric generatorwill be provided.

Integration of hydropower, with solar and wind renewable sources 61

Provision of two buffer water reservoirslocated at approx. 30m level difference onefrom another, needed from two points ofview: • due to the fact that the river flow will not

al low a constan t h igh-power

hydroelectric production and sporadicconsumers may overcome, for a shortperiod, up to 15 times the usualconsumption;

• due to the environmental impact (interms of the use of classical mineral

Fig. 3. Intelligent Energy System Block Scheme

Costel Boariu62

resources) we will try to reduce thecapacity of the batteries to the minimumpossible (1200 Ah).As a result, water in the upper basin,

with a capacity of 800 m3, will train, fallingin a 150 mm diameter pipe, a micro turbine,SHP1, with a capacity of max. 30 kW (whichwill operate in the 5 - 30 kW range). Thiscan cover any peak of consumption for aspecified period. This water tank will befilled from the bottom tank, which has acapacity of 1500 m3, through a 3kW pumpthat will use surplus energy from the system(from sources: solar, wind, generator orenergy in batteries).

The second micro-power plant, SHP 2, ofvery low power, about 2.5 kW, will also havea non-permanent operating mode. It will beplaced on the same pipeline but in adeviation from the first turbine and willactually be the pump that will work in areversible sense between 1- 2.5 Kw.

So we avoided installing an SHP - arestr ict ive condition imposed byenvironmental authorities- directly on theexisting water course. Because of theefficiency and the redundancy required, thepower inverter will be a cluster of 6 units.Studying climatic conditions and the windmap at the proposed location, the use of asmall wind power plant (400W) to operate atlow wind speeds specific to the locationswhere they could be located was adopted.

A power monitoring system will beconnected to all of this power plant, enablingintelligent energy production, managementand distribution of energy to consumers.The solar panels (about 15Kwpp) areproposed to be multilayered (last generation)technology that will generate current evenunder more diffused light conditions, specificto mountain areas).

All of this power-plant has aheat-laboratory in which the mentionedequipment as well as the rest of themonitoring, control, command anddistribution equipment will be installed.

4. Conclusions

We can assume that the hydroelectriccomponent, as estimated, has a potentiallyimportant contribution within the smartenergy system model in Vanatori NeamtNatural Park: a. as a renewable energysource, b. As a renewable energy storagesolution of the area's energy potential; b. asan optimal alternative to provide energy inan isolated area, with biodiversityconservation regulations, being anenvironmentally friendly solution (withoutimpact on the environment and biodiversityconservation status).

Economic aspectBy comparing the two methods of energy

storage: energy storage by pumping waterand storing energy in batteries, we estimatethat there are no big differences between thedepreciation periods of the two investments.

Environmental impactFrom the environmental perspective,

medium and long term environmentalimpact, the pumped storage solution is therecommended solution given that theenvironmental impact is insignificant in thiscase. By comparison, energy storage inbatteries is a method generating hazardouswastes with significant potential for theenvironment.

The developed model brings together thetwo storage methods in optimal proportionsso as not to generate significantenvironmental impact in the protectednatural area.

References

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Integration of hydropower, with solar and wind renewable sources 63

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