Entering into the sector of exploration of Oil andGas in 1998 the company developed the 1^st MCC container for the national drilling company Crosco - Integrated Drilling and Well Services Ltd. in 1999.

After 2000, the company had over 20 employees, with a continuous growth in the number and complexity of services. The acquired knowledge and experience is passed onto the younger staff. The company gains status as one of the leading companies in the field of installation, testing and commissioning of medium-voltage switchgears. Expert staff consisting of experienced electrical fitters, foremen, engineers and project managers successfully perform more and more demanding jobs. In addition to participating on projects related to the production, transmission and distribution of electric power, HELB is involved with the development of ancillary power plants for the developing road infrastructure in Croatia. The production of equipment and devices for the energy industry becomes an increasing part of the company's scope of work, and a special part of production and related research and development goes to the oil industry.

In 2005 the 1^st project has been performed in Russia when constructing a floating drilling rig.

In 2008 the company had more than 80 employees, organised in field teams equipped with all the necessary tools and devices. Along with the implementation of projects, HELB continuously invests in increasing the quality of service, in new equipment and tools and in the education of its employees.

Contracting of the entire power segment project, HELB has built the 1st wind park in Croatia connected to 110kV network at the 42MW wind farm Vrataruša in 2009. From that point on, the company has strongly entered the renewable energy sources and energy efficiency market. After conducting necessary training, HELB has built dozen of PV systems in Croatia and has installed several biogas power plants.

Starting in 2011 with the contract for UNDP–United Nations Development Program, today with a total of almost 700,000 m2 areas examined and 400 issued energy certificates, HELB is Croatian market leader in energy certification. From 2010 HELB performs works on the parameter setting and testing of numerical relay protection on mv switchgears and from 2011 HELB is licensed for assembly & testing of HV cable joints & terminations.

Croatia joins the EU in mid 2013 and immediately after that, HELB has performed works on the reconstruction of MV substations in Scotland, gaining important reference on the EU market. At the end of 2013, HELB entered the huge Chinese market, engaged by ABB for numerical relay protection on MV switchgears.

After finishing installation on 4 High voltage substations for the Ministry of electricity in the Kurdistan Region in 2014, HELB has started a more aggressive export strategy implementation. So in 2014, HELB was the exhibitor at Oil and Gas International Fairs: MEOS in Kingdom of Bahrain and OMC Ravenna in Italy.